Add smoke tests for UOM conversions and enhance frontend UOM management

- Implemented smoke tests for UOM directionality, ensuring conversions are one-directional and correctly validated.
- Added tests for receiving and selling items in different UOMs, verifying correct quantity handling and error responses.
- Created a UOM conversions panel in the frontend to allow users to manage UOM conversions for items.
- Introduced hooks for allowed UOMs to optimize fetching and caching of UOM data for document line forms.
- Developed utility functions for consistent UOM formatting and conversion handling across the application.

.gitignore

@@ -30,12 +30,13 @@ yarn-error.log*
 Thumbs.db
 .idea/
 
+# ── Playwright E2E (Testing/e2e) ──────────────────────────────────────
+Testing/e2e/playwright-report/
+Testing/e2e/test-results/
+Testing/e2e/.auth/
+Testing/e2e/blob-report/
+
 # ── Migrations ─────────────────────────────────────────────────────────
-# Reverted 2026-07-31: excluding new EF Core migrations while
-# ErpDbContextModelSnapshot.cs stayed tracked meant every `dotnet ef
-# migrations add` after the initial 4 silently produced a migration git would
-# never see, while the (tracked) snapshot's changes committed normally —
-# so the snapshot kept claiming tables existed that no migration in git
-# history ever created them. Confirmed live: 25 HRM tables + 11 Manufacturing
-# tables were missing from the actual database for exactly this reason.
-# Migrations now stay tracked like any other source file — commit them.
+# Each dev keeps EF Core migrations local; DB schema changes are announced
+# to the team instead of committed, so migration files aren't shared here.
+Migrations/

Backend/ERPCore/Controllers/BundleSalesController.cs

@@ -33,10 +33,11 @@ public sealed class BundleSalesController : ApiControllerBase
     [ProducesResponseType(typeof(PagedResponse<BundleSaleSummaryDto>), StatusCodes.Status200OK)]
     public async Task<ActionResult<PagedResponse<BundleSaleSummaryDto>>> List(
         [FromQuery] PageQuery query,
+        [FromQuery] BundleSaleStatus? status,
         [FromQuery] int? customerId,
         [FromQuery] int? warehouseId,
         CancellationToken ct)
-        => Ok(await _bundles.ListAsync(query, customerId, warehouseId, ct));
+        => Ok(await _bundles.ListAsync(query, status, customerId, warehouseId, ct));
 
     [HttpGet("{bundleSaleId:int}")]
     [ProducesResponseType(typeof(BundleSaleDto), StatusCodes.Status200OK)]

Backend/ERPCore/Controllers/ItemsController.cs

@@ -1,6 +1,7 @@
 using ERPCore.Domain.Enums;
 using ERPCore.Dtos.Common;
 using ERPCore.Dtos.Items;
+using ERPCore.Dtos.Uoms;
 using ERPCore.Services.Interfaces;
 using Microsoft.AspNetCore.Mvc;
 
@@ -11,8 +12,13 @@ namespace ERPCore.Controllers;
 public sealed class ItemsController : ApiControllerBase
 {
     private readonly IItemService _items;
+    private readonly IUomConverter _uomConverter;
 
-    public ItemsController(IItemService items) => _items = items;
+    public ItemsController(IItemService items, IUomConverter uomConverter)
+    {
+        _items = items;
+        _uomConverter = uomConverter;
+    }
 
     /// <summary>List items with optional filters and paging.</summary>
     [HttpGet]
@@ -88,4 +94,15 @@ public sealed class ItemsController : ApiControllerBase
     [ProducesResponseType(StatusCodes.Status404NotFound)]
     public async Task<ActionResult<ItemUomConversionsDto>> UpdateUomConversions(int itemId, [FromBody] UpdateUomConversionsRequest request, CancellationToken ct)
         => Ok(await _items.UpdateUomConversionsAsync(itemId, request, ct));
+
+    /// <summary>
+    /// The UOMs this item may be transacted in — its base UOM plus every UOM it has a
+    /// conversion from, each with the factor to base. Document line forms use this to offer
+    /// only units that will survive posting, instead of the whole global UOM list (FR-MD-02/03).
+    /// </summary>
+    [HttpGet("{itemId:int}/uoms")]
+    [ProducesResponseType(typeof(IReadOnlyList<AllowedUomDto>), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<IReadOnlyList<AllowedUomDto>>> GetAllowedUoms(int itemId, CancellationToken ct)
+        => Ok(await _uomConverter.GetAllowedUomsAsync(itemId, ct));
 }

Backend/ERPCore/Domain/Entities/BundleSaleLine.cs

@@ -11,9 +11,20 @@ public class BundleSaleLine
     public int ItemId { get; set; }
     public Item? Item { get; set; }
     public string Description { get; set; } = string.Empty;
+    /// <summary>Component quantity, in <see cref="UomId"/> — what the user entered.</summary>
     public decimal Qty { get; set; }
     public int UomId { get; set; }
     public Uom? Uom { get; set; }
+
+    /// <summary>
+    /// <see cref="Qty"/> restated in the item's base UOM, resolved once at save. Posting
+    /// consumes this. <see cref="Qty"/> and <see cref="UnitPrice"/> are always a matching
+    /// pair in <see cref="UomId"/>, so <see cref="LineTotal"/> stays value-correct.
+    /// </summary>
+    public decimal QtyBase { get; set; }
+
+    /// <summary>The factor used to derive <see cref="QtyBase"/>; 1 when the line is in base UOM.</summary>
+    public decimal ConversionFactor { get; set; } = 1m;
     public int WarehouseId { get; set; }
     public Warehouse? Warehouse { get; set; }
     public decimal UnitPrice { get; set; }

Backend/ERPCore/Domain/Entities/GrnLine.cs

@@ -34,8 +34,20 @@ public class GrnLine
     public int? BatchId { get; set; }
     public Batch? Batch { get; set; }
 
+    /// <summary>Quantity received, in <see cref="UomId"/> — what the user entered.</summary>
     public decimal Qty { get; set; }
 
+    /// <summary>
+    /// <see cref="Qty"/> restated in the item's base UOM, resolved once at line creation.
+    /// Confirm reads this snapshot rather than re-converting, so a conversion factor edited
+    /// between create and confirm cannot change what a saved GRN posts, and a later reversal
+    /// reproduces the original layer exactly.
+    /// </summary>
+    public decimal QtyBase { get; set; }
+
+    /// <summary>The factor used to derive <see cref="QtyBase"/>; 1 when the line is in base UOM.</summary>
+    public decimal ConversionFactor { get; set; } = 1m;
+
     /// <summary>Gross unit cost received at (entered, or PO price when omitted).</summary>
     public decimal UnitCost { get; set; }
 

Backend/ERPCore/Domain/Entities/PoLine.cs

@@ -21,8 +21,32 @@ public class PoLine
     public int WarehouseId { get; set; }
     public Warehouse? Warehouse { get; set; }
 
+    /// <summary>Quantity ordered, in <see cref="UomId"/>.</summary>
     public decimal Qty { get; set; }
     public decimal UnitPrice { get; set; }//
     public decimal Tax { get; set; }
+
+    /// <summary>
+    /// <see cref="Qty"/> restated in the item's base UOM, resolved once at line creation.
+    /// This — not <see cref="Qty"/> — is what open-quantity and close checks compare against,
+    /// because a GRN may legitimately receive against this line in a different UOM.
+    /// </summary>
+    public decimal QtyBase { get; set; }
+
+    /// <summary>The factor used to derive <see cref="QtyBase"/>; 1 when the line is in base UOM.</summary>
+    public decimal ConversionFactor { get; set; } = 1m;
+
+    /// <summary>
+    /// Accrues as GRNs confirm (FR-PROC-07), in <see cref="UomId"/>. <b>Denormalized for
+    /// display only</b> — it is derived by dividing <see cref="QtyReceivedBase"/> by the
+    /// factor, so it can drift. Never branch on it; use <see cref="QtyReceivedBase"/>.
+    /// </summary>
     public decimal QtyReceived { get; set; }
+
+    /// <summary>
+    /// Authoritative received-to-date in the item's base UOM. GRN confirm accrues here and
+    /// the PO close condition compares this against <see cref="QtyBase"/>, so receipts in a
+    /// UOM other than the PO's still add up correctly.
+    /// </summary>
+    public decimal QtyReceivedBase { get; set; }
 }

Backend/ERPCore/Domain/Entities/SalesInvoiceLine.cs

@@ -14,10 +14,24 @@ public class SalesInvoiceLine
 
     public string Description { get; set; } = string.Empty;
 
+    /// <summary>Quantity sold, in <see cref="UomId"/> — what the user entered and what prints.</summary>
     public decimal Qty { get; set; }
     public decimal FreeQty { get; set; }
     public int UomId { get; set; }
     public Uom? Uom { get; set; }
+
+    /// <summary>
+    /// <see cref="Qty"/> restated in the item's base UOM, resolved once at save. Posting
+    /// consumes stock against this snapshot — the FIFO engine is base-UOM only, so passing
+    /// the entered quantity would deplete the wrong amount whenever the line is not in base UOM.
+    /// </summary>
+    public decimal QtyBase { get; set; }
+
+    /// <summary><see cref="FreeQty"/> restated in the item's base UOM.</summary>
+    public decimal FreeQtyBase { get; set; }
+
+    /// <summary>The factor used to derive the base quantities; 1 when the line is in base UOM.</summary>
+    public decimal ConversionFactor { get; set; } = 1m;
     public int WarehouseId { get; set; }
     public Warehouse? Warehouse { get; set; }
 

Backend/ERPCore/Domain/Entities/SalesSlipLine.cs

@@ -14,10 +14,24 @@ public class SalesSlipLine
 
     public string Description { get; set; } = string.Empty;
 
+    /// <summary>Quantity sold, in <see cref="UomId"/> — what the user entered and what prints.</summary>
     public decimal Qty { get; set; }
     public decimal FreeQty { get; set; }
     public int UomId { get; set; }
     public Uom? Uom { get; set; }
+
+    /// <summary>
+    /// <see cref="Qty"/> restated in the item's base UOM, resolved once at save. Posting
+    /// consumes stock against this snapshot — the FIFO engine is base-UOM only, so passing
+    /// the entered quantity would deplete the wrong amount whenever the line is not in base UOM.
+    /// </summary>
+    public decimal QtyBase { get; set; }
+
+    /// <summary><see cref="FreeQty"/> restated in the item's base UOM.</summary>
+    public decimal FreeQtyBase { get; set; }
+
+    /// <summary>The factor used to derive the base quantities; 1 when the line is in base UOM.</summary>
+    public decimal ConversionFactor { get; set; } = 1m;
     public int WarehouseId { get; set; }
     public Warehouse? Warehouse { get; set; }
 

Backend/ERPCore/Dtos/Procurement/PurchaseOrderDtos.cs

@@ -5,9 +5,18 @@ namespace ERPCore.Dtos.Procurement;
 
 // Responses (docs/11 §3.3) ------------------------------------------------------
 
+/// <summary>
+/// A PO line. <paramref name="Qty"/> and <paramref name="QtyReceived"/> are in
+/// <paramref name="UomId"/> and are what the user sees; <paramref name="QtyBase"/> and
+/// <paramref name="QtyReceivedBase"/> are the item's base UOM and are what the server
+/// actually enforces — GRN over-receipt and the PO close condition both run on the base
+/// pair, because goods may legitimately be received in a different UOM from the one
+/// ordered. A client showing remaining/outstanding quantity should read the base pair.
+/// </summary>
 public sealed record PoLineDto(
     int PoLineId, int ItemId, int UomId, int WarehouseId,
-    decimal Qty, decimal UnitPrice, decimal Tax, decimal QtyReceived);
+    decimal Qty, decimal UnitPrice, decimal Tax, decimal QtyReceived,
+    decimal QtyBase = 0m, decimal QtyReceivedBase = 0m, decimal ConversionFactor = 1m);
 
 public sealed record PoTotalsDto(decimal SubTotal, decimal Tax, decimal GrandTotal, string Currency);
 

Backend/ERPCore/Dtos/Sales/BundleSaleDtos.cs

@@ -31,9 +31,10 @@ public sealed record BundleSaleTemplateSummaryDto(
     int BundleSaleTemplateId, string TemplateCode, string TemplateName, string? Description,
     EntityStatus Status, int LineCount, DateTime CreatedAt, DateTime? UpdatedAt);
 
+/// <summary>Quantities are in the item's base UOM — see <c>SalesInvoicePostingIssueDto</c>.</summary>
 public sealed record BundleSalePostingIssueDto(
     int BundleSaleLineId, int ItemId, string ItemSku, string ItemName, int WarehouseId,
-    decimal RequestedQty, decimal AvailableQty, decimal ShortQty);
+    decimal RequestedQty, decimal AvailableQty, decimal ShortQty, string BaseUomName = "");
 
 public sealed record BundleSalePostingCheckDto(
     int BundleSaleId, string BundleNo, BundleSaleStatus Status, bool CanPost,

Backend/ERPCore/Dtos/Sales/SalesInvoiceDtos.cs

@@ -24,9 +24,16 @@ public sealed record SalesInvoiceSummaryDto(
     string CustomerSnapshotName, int WarehouseId, SalesInvoiceType InvoiceType,
     SalesInvoiceStatus Status, SalesInvoiceTotalsDto Totals, DateTime CreatedAt);
 
+/// <summary>
+/// A line that cannot be posted for lack of stock. The three quantities are in the item's
+/// <b>base</b> UOM (on-hand only exists in base), which may differ from the UOM shown on the
+/// line — hence <paramref name="BaseUomName"/>: without it a line reading "2 BOX" produces
+/// an unexplained "requested 24, available 10".
+/// </summary>
 public sealed record SalesInvoicePostingIssueDto(
     int SalesInvoiceLineId, int ItemId, string ItemSku, string ItemName, int WarehouseId,
-    decimal RequestedQty, decimal AvailableQty, decimal ShortQty, bool IsFreeIssue);
+    decimal RequestedQty, decimal AvailableQty, decimal ShortQty, bool IsFreeIssue,
+    string BaseUomName = "");
 
 public sealed record SalesInvoicePostingCheckDto(
     int SalesInvoiceId, string InvoiceNo, SalesInvoiceStatus Status, bool CanPost,

Backend/ERPCore/Dtos/Sales/SalesSlipDtos.cs

@@ -23,9 +23,11 @@ public sealed record SalesSlipSummaryDto(
     string CustomerSnapshotName, int WarehouseId, SalesSlipStatus Status,
     SalesSlipTotalsDto Totals, DateTime CreatedAt);
 
+/// <summary>Quantities are in the item's base UOM — see <c>SalesInvoicePostingIssueDto</c>.</summary>
 public sealed record SalesSlipPostingIssueDto(
     int SalesSlipLineId, int ItemId, string ItemSku, string ItemName, int WarehouseId,
-    decimal RequestedQty, decimal AvailableQty, decimal ShortQty, bool IsFreeIssue);
+    decimal RequestedQty, decimal AvailableQty, decimal ShortQty, bool IsFreeIssue,
+    string BaseUomName = "");
 
 public sealed record SalesSlipPostingCheckDto(
     int SalesSlipId, string SlipNo, SalesSlipStatus Status, bool CanPost,

Backend/ERPCore/Dtos/Stock/StockDtos.cs

@@ -2,16 +2,23 @@ using ERPCore.Domain.Enums;
 
 namespace ERPCore.Dtos.Stock;
 
+// Every quantity a stock endpoint returns is in the item's base UOM — stock, layers and the
+// ledger are base-only by construction. The BaseUomId/BaseUomName pair on each of these DTOs
+// exists so a client can *label* those figures; without it every stock screen renders a bare
+// number the user has to guess the unit of. They are never a conversion instruction.
+
 /// <summary>Stock enquiry (docs/11 §5.1). available = onHand − onHold − reserved − inTransit(out).</summary>
 public sealed record StockOnHandDto(
     int ItemId, int WarehouseId, decimal OnHand, decimal Available,
-    decimal OnHold, decimal InTransit, decimal Reserved, DateTime AsOf);
+    decimal OnHold, decimal InTransit, decimal Reserved, DateTime AsOf,
+    int BaseUomId = 0, string BaseUomName = "");
 
 /// <summary>A stock-ledger row (docs/11 §5.2).</summary>
 public sealed record StockLedgerRowDto(
     int LedgerId, int ItemId, int WarehouseId, int? BinId, int? BatchId, int? SerialId,
     Direction Direction, decimal QtyBase, decimal UnitCost, decimal Value, decimal RunningBalance,
-    string SourceDocType, int SourceDocId, int UserId, DateTime CreatedAt);
+    string SourceDocType, int SourceDocId, int UserId, DateTime CreatedAt,
+    int BaseUomId = 0, string BaseUomName = "");
 
 /// <summary>An open FIFO layer in a valuation (docs/11 §5.3).</summary>
 public sealed record StockValuationLayerDto(int LayerId, decimal QtyRemaining, decimal UnitCost, decimal Value, DateTime ReceiptDate);
@@ -19,4 +26,5 @@ public sealed record StockValuationLayerDto(int LayerId, decimal QtyRemaining, d
 /// <summary>Valuation of on-hand stock from open FIFO layers (docs/11 §5.3).</summary>
 public sealed record StockValuationDto(
     int ItemId, int WarehouseId, IReadOnlyList<StockValuationLayerDto> Layers,
-    decimal TotalQty, decimal TotalValue, string Currency, string CostingMethod);
+    decimal TotalQty, decimal TotalValue, string Currency, string CostingMethod,
+    int BaseUomId = 0, string BaseUomName = "");

Backend/ERPCore/Dtos/Uoms/UomDtos.cs

@@ -9,3 +9,12 @@ public sealed class CreateUomRequest
 {
     [Required, StringLength(50)] public string Name { get; set; } = string.Empty;
 }
+
+/// <summary>
+/// A UOM an item may actually be transacted in: its base UOM (<paramref name="Factor"/> 1,
+/// <paramref name="IsBase"/> true) plus every UOM it has a conversion from. Backs both
+/// entry-time validation and <c>GET /items/{itemId}/uoms</c>, so the client can offer only
+/// units that will survive posting instead of the whole global list.
+/// </summary>
+/// <param name="Factor">Multiply a quantity in this UOM by <paramref name="Factor"/> to get base UOM.</param>
+public sealed record AllowedUomDto(int UomId, string Name, decimal Factor, bool IsBase);

Backend/ERPCore/Infra/Persistence/Configurations/BundleSaleLineConfiguration.cs

@@ -12,6 +12,8 @@ public sealed class BundleSaleLineConfiguration : IEntityTypeConfiguration<Bundl
         builder.HasKey(x => x.BundleSaleLineId);
         builder.Property(x => x.Description).IsRequired().HasMaxLength(200);
         builder.Property(x => x.Qty).HasPrecision(18, 4);
+        builder.Property(x => x.QtyBase).HasPrecision(18, 4);
+        builder.Property(x => x.ConversionFactor).HasPrecision(18, 6).HasDefaultValue(1m);
         builder.Property(x => x.UnitPrice).HasPrecision(18, 4);
         builder.Property(x => x.LineTotal).HasPrecision(18, 4);
         builder.Property(x => x.IncludeInBundle).HasDefaultValue(true);

Backend/ERPCore/Infra/Persistence/Configurations/GrnConfiguration.cs

@@ -36,6 +36,8 @@ public sealed class GrnLineConfiguration : IEntityTypeConfiguration<GrnLine>
         builder.HasKey(l => l.GrnLineId);
 
         builder.Property(l => l.Qty).HasPrecision(18, 4);
+        builder.Property(l => l.QtyBase).HasPrecision(18, 4);
+        builder.Property(l => l.ConversionFactor).HasPrecision(18, 6).HasDefaultValue(1m);
         builder.Property(l => l.UnitCost).HasPrecision(18, 6);
         builder.Property(l => l.PoUnitPrice).HasPrecision(18, 6);
         builder.Property(l => l.DiscountPct).HasPrecision(9, 4);

Backend/ERPCore/Infra/Persistence/Configurations/PurchaseOrderConfiguration.cs

@@ -49,6 +49,9 @@ public sealed class PoLineConfiguration : IEntityTypeConfiguration<PoLine>
         builder.HasKey(l => l.PoLineId);
 
         builder.Property(l => l.Qty).HasPrecision(18, 4);
+        builder.Property(l => l.QtyBase).HasPrecision(18, 4);
+        builder.Property(l => l.QtyReceivedBase).HasPrecision(18, 4);
+        builder.Property(l => l.ConversionFactor).HasPrecision(18, 6).HasDefaultValue(1m);
         builder.Property(l => l.UnitPrice).HasPrecision(18, 4);
         builder.Property(l => l.Tax).HasPrecision(9, 4);
         builder.Property(l => l.QtyReceived).HasPrecision(18, 4);

Backend/ERPCore/Infra/Persistence/Configurations/SalesInvoiceConfiguration.cs

@@ -70,6 +70,9 @@ public sealed class SalesInvoiceLineConfiguration : IEntityTypeConfiguration<Sal
 
         builder.Property(x => x.Qty).HasPrecision(18, 4);
         builder.Property(x => x.FreeQty).HasPrecision(18, 4);
+        builder.Property(x => x.QtyBase).HasPrecision(18, 4);
+        builder.Property(x => x.FreeQtyBase).HasPrecision(18, 4);
+        builder.Property(x => x.ConversionFactor).HasPrecision(18, 6).HasDefaultValue(1m);
         builder.Property(x => x.UnitPrice).HasPrecision(18, 4);
         builder.Property(x => x.BaseCost).HasPrecision(18, 4);
         builder.Property(x => x.DiscountPct).HasPrecision(9, 4);

Backend/ERPCore/Infra/Persistence/Configurations/SalesSlipConfiguration.cs

@@ -70,6 +70,9 @@ public sealed class SalesSlipLineConfiguration : IEntityTypeConfiguration<SalesS
 
         builder.Property(x => x.Qty).HasPrecision(18, 4);
         builder.Property(x => x.FreeQty).HasPrecision(18, 4);
+        builder.Property(x => x.QtyBase).HasPrecision(18, 4);
+        builder.Property(x => x.FreeQtyBase).HasPrecision(18, 4);
+        builder.Property(x => x.ConversionFactor).HasPrecision(18, 6).HasDefaultValue(1m);
         builder.Property(x => x.UnitPrice).HasPrecision(18, 4);
         builder.Property(x => x.BaseCost).HasPrecision(18, 4);
         builder.Property(x => x.DiscountPct).HasPrecision(9, 4);

Backend/ERPCore/Infra/Persistence/Configurations/UomConversionConfiguration.cs

@@ -30,5 +30,9 @@ public sealed class UomConversionConfiguration : IEntityTypeConfiguration<UomCon
 
         // One conversion per (item, from, to) triple.
         builder.HasIndex(c => new { c.ItemId, c.FromUomId, c.ToUomId }).IsUnique();
+
+        // The API guards this too, but UomConverter divides unit cost by the factor — a zero
+        // reaching the table from a seeder or direct SQL would be a divide-by-zero at post time.
+        builder.ToTable(t => t.HasCheckConstraint("ck_uom_conversions_factor_positive", "\"Factor\" > 0"));
     }
 }

Backend/ERPCore/Services/BundleSaleService.cs

@@ -23,6 +23,7 @@ public sealed class BundleSaleService : IBundleSaleService
     private readonly IRepository<Warehouse> _warehouses;
     private readonly IRepository<User> _users;
     private readonly ISalesDomainService _sales;
+    private readonly IUomConverter _uomConverter;
     private readonly ISalesPostingService _posting;
     private readonly ICurrentUser _currentUser;
     private readonly INumberSequenceService _numbers;
@@ -37,6 +38,7 @@ public sealed class BundleSaleService : IBundleSaleService
         IRepository<Warehouse> warehouses,
         IRepository<User> users,
         ISalesDomainService sales,
+        IUomConverter uomConverter,
         ISalesPostingService posting,
         ICurrentUser currentUser,
         INumberSequenceService numbers,
@@ -50,6 +52,7 @@ public sealed class BundleSaleService : IBundleSaleService
         _warehouses = warehouses;
         _users = users;
         _sales = sales;
+        _uomConverter = uomConverter;
         _posting = posting;
         _currentUser = currentUser;
         _numbers = numbers;
@@ -85,7 +88,7 @@ public sealed class BundleSaleService : IBundleSaleService
                 x.BundleSaleTemplateLineId, x.ItemId, x.UomId, x.WarehouseId, x.Qty, x.UnitPrice, x.IncludeInBundle, x.SortOrder)).ToList());
     }
 
-    public async Task<PagedResponse<BundleSaleSummaryDto>> ListAsync(PageQuery query, int? customerId, int? warehouseId, CancellationToken ct = default)
+    public async Task<PagedResponse<BundleSaleSummaryDto>> ListAsync(PageQuery query, BundleSaleStatus? status, int? customerId, int? warehouseId, CancellationToken ct = default)
     {
         IQueryable<BundleSale> q = _bundles.Query().AsNoTracking().Include(x => x.Lines);
         if (!string.IsNullOrWhiteSpace(query.Q))
@@ -93,6 +96,7 @@ public sealed class BundleSaleService : IBundleSaleService
             var term = query.Q.Trim();
             q = q.Where(x => EF.Functions.ILike(x.BundleNo, $"%{term}%") || EF.Functions.ILike(x.BundleName, $"%{term}%") || EF.Functions.ILike(x.BundleCode, $"%{term}%"));
         }
+        if (status is not null) q = q.Where(x => x.Status == status);
         if (customerId is not null) q = q.Where(x => x.CustomerId == customerId);
         if (warehouseId is not null) q = q.Where(x => x.WarehouseId == warehouseId);
         var total = await q.CountAsync(ct);
@@ -204,21 +208,30 @@ public sealed class BundleSaleService : IBundleSaleService
         {
             if (r.Qty <= 0)
                 throw new DomainException(ErrorCodes.Validation, "Bundle line quantity must be greater than zero.", 422);
-            if (r.WarehouseId != warehouseId)
-                throw new DomainException(ErrorCodes.Validation,
-                    $"Bundle line warehouse {r.WarehouseId} must match header warehouse {warehouseId}.", 422);
+
+            // Bundle sales use the header warehouse as the source of truth for stock and pricing.
+            // Keep any per-line warehouse input from drifting away from the header.
+            var lineWarehouseId = warehouseId;
+
             var item = await _items.Query().AsNoTracking().FirstAsync(x => x.ItemId == r.ItemId, ct);
-            await _sales.ValidateSalesLineAsync(warehouseId, r.ItemId, r.UomId, r.WarehouseId, r.Qty, 0m, null, ct);
-            var resolved = await _sales.ResolveLinePriceAsync(r.ItemId, r.WarehouseId, r.UnitPrice, true, ct);
-            var calc = _sales.ComputeLine(r.Qty, 0m, resolved.UnitPrice, SalesDiscountMode.Amount, 0m, 0m, 0m, 0m, false);
+            await _sales.ValidateSalesLineAsync(warehouseId, r.ItemId, r.UomId, lineWarehouseId, r.Qty, 0m, null, ct);
+
+            // Keep the entered UOM on the line and snapshot the base quantity beside it, the
+            // same shape as invoices and slips. Qty and UnitPrice stay a matching pair in the
+            // entered UOM so LineTotal — which Recalculate rolls into the header — is the
+            // value the user priced; only QtyBase crosses into the base-UOM stock engine.
+            var factor = await _uomConverter.ResolveFactorAsync(item, r.UomId, ct);
+            var calc = _sales.ComputeLine(r.Qty, 0m, r.UnitPrice, SalesDiscountMode.Amount, 0m, 0m, 0m, 0m, false);
             lines.Add(new BundleSaleLine
             {
                 ItemId = r.ItemId,
                 Description = item.Name,
                 Qty = r.Qty,
                 UomId = r.UomId,
-                WarehouseId = r.WarehouseId,
-                UnitPrice = resolved.UnitPrice,
+                QtyBase = UomConverter.ApplyFactor(r.Qty, factor),
+                ConversionFactor = factor,
+                WarehouseId = lineWarehouseId,
+                UnitPrice = r.UnitPrice,
                 LineTotal = calc.LineTotal,
                 IncludeInBundle = r.IncludeInBundle,
                 IsComponent = true,

Backend/ERPCore/Services/GrnService.cs

@@ -7,6 +7,7 @@ using ERPCore.Infra.Auth;
 using ERPCore.Infra.UoW;
 using ERPCore.Repositories.Interfaces;
 using ERPCore.Services.Interfaces;
+using ERPCore.Services.Stock;
 using ERPCore.System.Errors;
 using Microsoft.EntityFrameworkCore;
 
@@ -138,6 +139,12 @@ public sealed class GrnService : IGrnService
             if (input.BinId is not null && !await _bins.Query().AnyAsync(b => b.BinId == input.BinId && b.WarehouseId == request.WarehouseId, ct))
                 throw new DomainException(ErrorCodes.Validation, $"Bin {input.BinId} is not in warehouse {request.WarehouseId}.", 422);
 
+            // Resolve the base quantity at entry. This rejects a UOM the item cannot be
+            // received in while the GRN is still a draft, and snapshots the factor so confirm
+            // (and any later reversal) reproduces exactly this quantity.
+            var conversionFactor = await _uomConverter.ResolveFactorAsync(item, input.UomId, ct);
+            var qtyBaseEntered = UomConverter.ApplyFactor(input.Qty, conversionFactor);
+
             // Cost: for a PO line, the PO price is used unless an override is entered (then it
             // wins and a variance is recorded against the PO snapshot — docs/02-SECURITY C.3,
             // revised). Direct receipts always use the entered cost.
@@ -150,10 +157,13 @@ public sealed class GrnService : IGrnService
                 if (poLine.ItemId != input.ItemId)
                     throw new DomainException(ErrorCodes.Validation, $"PO line {input.PoLineId} is for a different item.", 422);
 
-                var openQty = poLine.Qty - poLine.QtyReceived;
-                if (input.Qty > openQty * (1 + OverReceiptTolerance))
+                // Compare in base UOM: a GRN may legitimately receive in a different UOM from
+                // the one the PO was raised in (10 BOX ordered, 120 PCS delivered), and
+                // comparing the two raw numbers would reject that valid receipt.
+                var openQtyBase = poLine.QtyBase - poLine.QtyReceivedBase;
+                if (qtyBaseEntered > openQtyBase * (1 + OverReceiptTolerance))
                     throw new DomainException(ErrorCodes.OverReceiptTolerance,
-                        $"Receiving {input.Qty} exceeds the open quantity {openQty} on PO line {input.PoLineId}.", 422);
+                        $"Receiving {input.Qty} ({qtyBaseEntered} base) exceeds the open quantity {openQtyBase} base on PO line {input.PoLineId}.", 422);
 
                 poUnitPrice = poLine.UnitPrice;
                 unitCost = input.UnitCost > 0 ? input.UnitCost : poLine.UnitPrice;
@@ -178,6 +188,8 @@ public sealed class GrnService : IGrnService
                 BinId = input.BinId,
                 Batch = batch, // navigation so EF fixes up BatchId once the batch is inserted
                 Qty = input.Qty,
+                QtyBase = qtyBaseEntered,
+                ConversionFactor = conversionFactor,
                 UnitCost = unitCost,
                 PoUnitPrice = poUnitPrice,
                 DiscountPct = input.DiscountPct,
@@ -234,10 +246,13 @@ public sealed class GrnService : IGrnService
         {
             foreach (var line in grn.Lines.OrderBy(l => l.GrnLineId))
             {
-                var item = await _items.Query().AsNoTracking().FirstAsync(i => i.ItemId == line.ItemId, token);
                 // FIFO layer costs at the after-discount net price; VAT is recoverable and never
-                // enters stock value (docs/10 FR-GRN-06, revised).
-                var (qtyBase, unitCostBase) = await ToBaseAsync(item, line.UomId, line.Qty, line.NetUnitCost, token);
+                // enters stock value (docs/10 FR-GRN-06, revised). Quantity and cost come from
+                // the factor snapshotted at line creation, not a fresh lookup — see GrnLine.QtyBase.
+                var qtyBase = line.QtyBase;
+                var unitCostBase = line.ConversionFactor == 1m
+                    ? line.NetUnitCost
+                    : Math.Round(line.NetUnitCost / line.ConversionFactor, 6, MidpointRounding.AwayFromZero);
 
                 var layer = await _fifo.CreateInboundLayerAsync(
                     line.ItemId, grn.WarehouseId, line.BatchId, null, line.GrnLineId,
@@ -258,7 +273,13 @@ public sealed class GrnService : IGrnService
                 if (line.PoLineId is not null)
                 {
                     var poLine = await _poLines.GetByIdAsync(line.PoLineId.Value, token);
-                    if (poLine is not null) poLine.QtyReceived += line.Qty;
+                    if (poLine is not null)
+                    {
+                        // Accrue in base so receipts in a UOM other than the PO's still add up.
+                        // QtyReceived is kept in the PO's own UOM for display only.
+                        poLine.QtyReceivedBase += qtyBase;
+                        poLine.QtyReceived = UomConverter.FromBase(poLine.QtyReceivedBase, poLine.ConversionFactor);
+                    }
                 }
             }
 
@@ -345,22 +366,14 @@ public sealed class GrnService : IGrnService
         return created; // linked via GrnLine.Batch navigation; FK fixed up on SaveChanges
     }
 
-    /// <summary>
-    /// Delegates to the shared <see cref="IUomConverter"/>. This was a private method here
-    /// until manufacturing needed the same conversion for stage stock inputs; behaviour is
-    /// identical, so receive costing is unchanged.
-    /// </summary>
-    private Task<(decimal QtyBase, decimal UnitCostBase)> ToBaseAsync(
-        Item item, int uomId, decimal qty, decimal unitCostPerUom, CancellationToken ct)
-        => _uomConverter.ToBaseAsync(item, uomId, qty, unitCostPerUom, ct);
-
     private async Task UpdatePoStatusAsync(int? poId, CancellationToken ct)
     {
         if (poId is null) return;
         var po = await _pos.Query().Include(p => p.Lines).FirstOrDefaultAsync(p => p.PoId == poId, ct);
         if (po is null) return;
 
-        po.Status = po.Lines.All(l => l.QtyReceived >= l.Qty)
+        // Base-vs-base: QtyReceived is a denormalized display figure and must not gate closing.
+        po.Status = po.Lines.All(l => l.QtyReceivedBase >= l.QtyBase)
             ? PurchaseOrderStatus.FullyReceived
             : PurchaseOrderStatus.PartiallyReceived;
         po.UpdatedAt = DateTime.UtcNow;

Backend/ERPCore/Services/Interfaces/IBundleSaleService.cs

@@ -1,4 +1,5 @@
 using ERPCore.Common.Http;
+using ERPCore.Domain.Enums;
 using ERPCore.Dtos.Common;
 using ERPCore.Dtos.Sales;
 
@@ -8,7 +9,7 @@ public interface IBundleSaleService
 {
     Task<PagedResponse<BundleSaleTemplateSummaryDto>> ListTemplatesAsync(PageQuery query, CancellationToken ct = default);
     Task<BundleSaleTemplateDto?> GetTemplateAsync(int bundleSaleTemplateId, CancellationToken ct = default);
-    Task<PagedResponse<BundleSaleSummaryDto>> ListAsync(PageQuery query, int? customerId, int? warehouseId, CancellationToken ct = default);
+    Task<PagedResponse<BundleSaleSummaryDto>> ListAsync(PageQuery query, BundleSaleStatus? status, int? customerId, int? warehouseId, CancellationToken ct = default);
     Task<BundleSaleDto?> GetAsync(int bundleSaleId, CancellationToken ct = default);
     Task<BundleSalePostingCheckDto> CheckPostingAsync(int bundleSaleId, CancellationToken ct = default);
     Task<BundleSaleDto> CreateAsync(CreateBundleSaleRequest request, CancellationToken ct = default);

Backend/ERPCore/Services/Interfaces/IUomConverter.cs

@@ -1,4 +1,5 @@
 using ERPCore.Domain.Entities;
+using ERPCore.Dtos.Uoms;
 
 namespace ERPCore.Services.Interfaces;
 
@@ -32,4 +33,29 @@ public interface IUomConverter
     /// consumes, not from the document).
     /// </summary>
     Task<decimal> ToBaseQtyAsync(Item item, int uomId, decimal qty, CancellationToken ct = default);
+
+    /// <summary>
+    /// The single factor lookup every other method is built on: <c>1</c> when
+    /// <paramref name="uomId"/> is already the base UOM, otherwise the item's conversion
+    /// factor from that UOM to base. Throws 422 when none is defined.
+    /// </summary>
+    /// <remarks>
+    /// Callers that persist a line should store this alongside the quantity so posting
+    /// reads a snapshot instead of re-resolving — a factor edited between save and post
+    /// must never change what an already-saved document posts.
+    /// </remarks>
+    Task<decimal> ResolveFactorAsync(Item item, int uomId, CancellationToken ct = default);
+
+    /// <summary>
+    /// Every UOM <paramref name="itemId"/> may be transacted in — base UOM first, then each
+    /// conversion source, ordered by name.
+    /// </summary>
+    Task<IReadOnlyList<AllowedUomDto>> GetAllowedUomsAsync(int itemId, CancellationToken ct = default);
+
+    /// <summary>
+    /// Entry-time guard: throws 422 naming the allowed units when <paramref name="uomId"/>
+    /// is neither the item's base UOM nor a UOM it has a conversion from. Call this when a
+    /// document line is created so the user is told at entry, not by a cryptic failure at post.
+    /// </summary>
+    Task ValidateUomAsync(Item item, int uomId, CancellationToken ct = default);
 }

Backend/ERPCore/Services/ItemService.cs

@@ -148,6 +148,15 @@ public sealed class ItemService : IItemService
             request.CategoryId, request.SubCategoryId, request.BrandId,
             request.BaseUomId, request.DefaultVendorId, ct);
 
+        // Conversions are stored as <other> → base. Repointing the base UOM would leave every
+        // existing row aimed at a UOM that is no longer the base: invisible to IUomConverter,
+        // filtered out of the allowed-UOM list, and unfixable through the conversions editor
+        // (which would 422 on re-save). Make the user clear them deliberately instead.
+        if (request.BaseUomId != item.BaseUomId && item.UomConversions.Count > 0)
+            throw new DomainException(ErrorCodes.Validation,
+                $"Item {item.Sku} has {item.UomConversions.Count} UOM conversion(s) defined against base UOM {item.BaseUomId}. " +
+                "Remove them before changing the base UOM, then re-enter them against the new base.", 422);
+
         item.Sku = request.Sku.Trim();
         item.Name = request.Name.Trim();
         item.Description = request.Description;
@@ -240,6 +249,26 @@ public sealed class ItemService : IItemService
             if (!await _uoms.Query().AnyAsync(u => u.UomId == uomId, ct))
                 throw new DomainException(ErrorCodes.Validation, $"UOM {uomId} does not exist.", 422);
 
+        // Conversions are one-directional: always <other> → base. IUomConverter looks up
+        // exactly that shape and never inverts a factor, so a row saved the other way round
+        // would persist happily, render in the UI, and then be invisible at post time. Reject
+        // it here instead of letting it fail later as an unexplained 422.
+        foreach (var c in request.Conversions)
+        {
+            if (c.ToUom != item.BaseUomId)
+                throw new DomainException(ErrorCodes.Validation,
+                    $"Conversion {c.FromUom} → {c.ToUom} is invalid: conversions must convert to the item's base UOM ({item.BaseUomId}).", 422);
+            if (c.FromUom == c.ToUom)
+                throw new DomainException(ErrorCodes.Validation,
+                    $"Conversion {c.FromUom} → {c.ToUom} is invalid: a UOM cannot convert to itself.", 422);
+            if (c.FromUom == item.BaseUomId)
+                throw new DomainException(ErrorCodes.Validation,
+                    "The base UOM converts to itself implicitly (factor 1) and must not be listed.", 422);
+            if (c.Factor <= 0m)
+                throw new DomainException(ErrorCodes.Validation,
+                    $"Conversion {c.FromUom} → {c.ToUom} must have a factor greater than zero.", 422);
+        }
+
         foreach (var stale in item.UomConversions.Where(c => request.Conversions.All(r => r.FromUom != c.FromUomId || r.ToUom != c.ToUomId)).ToList())
             item.UomConversions.Remove(stale);
         foreach (var input in request.Conversions)

Backend/ERPCore/Services/Production/ProductionTemplateService.cs

@@ -27,6 +27,7 @@ public sealed class ProductionTemplateService : IProductionTemplateService
     private readonly IRepository<Item> _items;
     private readonly IRepository<Uom> _uoms;
     private readonly IRepository<ProductionRun> _runs;
+    private readonly IUomConverter _uomConverter;
     private readonly IUnitOfWork _uow;
     private readonly ICurrentUser _currentUser;
 
@@ -34,8 +35,9 @@ public sealed class ProductionTemplateService : IProductionTemplateService
         IRepository<ProductionTemplate> templates, IRepository<TemplateStage> stages,
         IRepository<StageInput> inputs, IRepository<StageOutput> outputs, IRepository<StageEdge> edges,
         IRepository<Item> items, IRepository<Uom> uoms, IRepository<ProductionRun> runs,
-        IUnitOfWork uow, ICurrentUser currentUser)
+        IUomConverter uomConverter, IUnitOfWork uow, ICurrentUser currentUser)
     {
+        _uomConverter = uomConverter;
         _templates = templates;
         _stages = stages;
         _inputs = inputs;
@@ -291,6 +293,20 @@ public sealed class ProductionTemplateService : IProductionTemplateService
             throw new DomainException(ErrorCodes.Validation,
                 $"UOM(s) {string.Join(", ", missingUoms)} do not exist.", 422);
 
+        // Existence is not enough: a stage line's UOM must be one its own item can convert to
+        // base, or the run would fail with a 422 at stage start — long after the template was
+        // authored. Check the (item, uom) pairing here, while the template is being saved.
+        var itemUomPairs = request.Stages
+            .SelectMany(s => s.Inputs.Select(i => (i.ItemId, i.UomId)).Concat(s.Outputs.Select(o => (o.ItemId, o.UomId))))
+            .Distinct().ToList();
+
+        foreach (var (itemId, uomId) in itemUomPairs)
+        {
+            var item = await _items.Query().AsNoTracking().FirstOrDefaultAsync(i => i.ItemId == itemId, ct);
+            if (item is not null)
+                await _uomConverter.ValidateUomAsync(item, uomId, ct);
+        }
+
         // Annotations go into jsonb unvalidated by anything else, so pin the one field the
         // client renders off. Unknown kinds would round-trip fine but draw nothing.
         var badKinds = request.Annotations

Backend/ERPCore/Services/PurchaseOrderService.cs

@@ -8,6 +8,7 @@ using ERPCore.Infra.Auth;
 using ERPCore.Infra.UoW;
 using ERPCore.Repositories.Interfaces;
 using ERPCore.Services.Interfaces;
+using ERPCore.Services.Stock;
 using ERPCore.System.Errors;
 using Microsoft.EntityFrameworkCore;
 
@@ -28,6 +29,7 @@ public sealed class PurchaseOrderService : IPurchaseOrderService
     private readonly IRepository<Item> _items;
     private readonly IRepository<Uom> _uoms;
     private readonly IRepository<Warehouse> _warehouses;
+    private readonly IUomConverter _uomConverter;
     private readonly INumberSequenceService _numbers;
     private readonly ICurrentUser _currentUser;
     private readonly IUnitOfWork _uow;
@@ -35,8 +37,9 @@ public sealed class PurchaseOrderService : IPurchaseOrderService
     public PurchaseOrderService(
         IRepository<PurchaseOrder> pos, IRepository<Vendor> vendors, IRepository<Requisition> requisitions,
         IRepository<Item> items, IRepository<Uom> uoms, IRepository<Warehouse> warehouses,
-        INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow)
+        IUomConverter uomConverter, INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow)
     {
+        _uomConverter = uomConverter;
         _pos = pos;
         _vendors = vendors;
         _requisitions = requisitions;
@@ -83,6 +86,7 @@ public sealed class PurchaseOrderService : IPurchaseOrderService
     {
         await ValidateReferencesAsync(request.VendorId, request.RequisitionId, request.Lines, ct);
         var actor = _currentUser.AuditUserId;
+        var lines = await ToLinesAsync(request.Lines, ct);
 
         var po = await _uow.ExecuteInTransactionAsync(async token =>
         {
@@ -98,7 +102,7 @@ public sealed class PurchaseOrderService : IPurchaseOrderService
                 Status = request.SaveAsDraft ? PurchaseOrderStatus.Draft : PurchaseOrderStatus.Approved,
                 CreatedBy = actor,
                 CreatedAt = DateTime.UtcNow,
-                Lines = request.Lines.Select(ToLine).ToList()
+                Lines = lines
             };
             await _pos.AddAsync(entity, token);
             return entity;
@@ -129,8 +133,8 @@ public sealed class PurchaseOrderService : IPurchaseOrderService
 
         // Full line replacement (Phase 1: no receipts yet, so qtyReceived is 0 on every line).
         po.Lines.Clear();
-        foreach (var input in request.Lines)
-            po.Lines.Add(ToLine(input));
+        foreach (var line in await ToLinesAsync(request.Lines, ct))
+            po.Lines.Add(line);
 
         try
         {
@@ -219,16 +223,34 @@ public sealed class PurchaseOrderService : IPurchaseOrderService
     // Supersedes Phase-1 Option B "freely editable while open" — see docs/10 FR-PROC-05.
     private static bool IsEditable(PurchaseOrderStatus status) => status is PurchaseOrderStatus.Draft;
 
-    private static PoLine ToLine(CreatePoLineInput l) => new()
+    /// <summary>
+    /// Materialises request lines, resolving each one's base quantity up front. Resolving here
+    /// rejects a UOM the item cannot be ordered in at entry time, and gives GRN receipt matching
+    /// a stable base figure to compare against regardless of the UOM the goods arrive in.
+    /// </summary>
+    private async Task<List<PoLine>> ToLinesAsync(IReadOnlyCollection<CreatePoLineInput> inputs, CancellationToken ct)
     {
-        ItemId = l.ItemId,
-        UomId = l.UomId,
-        WarehouseId = l.WarehouseId,
-        Qty = l.Qty,
-        UnitPrice = l.UnitPrice,
-        Tax = l.Tax,
-        QtyReceived = 0
-    };
+        var lines = new List<PoLine>(inputs.Count);
+        foreach (var l in inputs)
+        {
+            var item = await _items.Query().AsNoTracking().FirstAsync(i => i.ItemId == l.ItemId, ct);
+            var factor = await _uomConverter.ResolveFactorAsync(item, l.UomId, ct);
+            lines.Add(new PoLine
+            {
+                ItemId = l.ItemId,
+                UomId = l.UomId,
+                WarehouseId = l.WarehouseId,
+                Qty = l.Qty,
+                QtyBase = UomConverter.ApplyFactor(l.Qty, factor),
+                ConversionFactor = factor,
+                UnitPrice = l.UnitPrice,
+                Tax = l.Tax,
+                QtyReceived = 0,
+                QtyReceivedBase = 0
+            });
+        }
+        return lines;
+    }
 
     private static PoTotalsDto ComputeTotals(IEnumerable<PoLine> lines)
     {
@@ -276,5 +298,6 @@ public sealed class PurchaseOrderService : IPurchaseOrderService
         p.PoId, p.DocNo, p.VendorId, p.RequisitionId, p.Status, p.ApprovalRequired,
         p.CreatedBy, p.CreatedAt, p.UpdatedAt, ComputeTotals(p.Lines),
         p.Lines.OrderBy(l => l.PoLineId).Select(l => new PoLineDto(
-            l.PoLineId, l.ItemId, l.UomId, l.WarehouseId, l.Qty, l.UnitPrice, l.Tax, l.QtyReceived)).ToList());
+            l.PoLineId, l.ItemId, l.UomId, l.WarehouseId, l.Qty, l.UnitPrice, l.Tax, l.QtyReceived,
+            l.QtyBase, l.QtyReceivedBase, l.ConversionFactor)).ToList());
 }

Backend/ERPCore/Services/SalesInvoiceService.cs

@@ -25,6 +25,7 @@ public sealed class SalesInvoiceService : ISalesInvoiceService
     private readonly ISalesPostingService _posting;
     private readonly ISalesMappingService _mapping;
     private readonly ISalesDocumentWorkflowService _workflow;
+    private readonly IUomConverter _uomConverter;
     private readonly ICurrentUser _currentUser;
     private readonly INumberSequenceService _numbers;
     private readonly IUnitOfWork _uow;
@@ -32,9 +33,10 @@ public sealed class SalesInvoiceService : ISalesInvoiceService
     public SalesInvoiceService(
         IRepository<SalesInvoice> invoices, IRepository<Customer> customers, IRepository<Item> items,
         IRepository<Uom> uoms, IRepository<Warehouse> warehouses, ISalesDomainService sales, ISalesPostingService posting, ISalesMappingService mapping,
-        ISalesDocumentWorkflowService workflow,
+        ISalesDocumentWorkflowService workflow, IUomConverter uomConverter,
         ICurrentUser currentUser, INumberSequenceService numbers, IUnitOfWork uow)
     {
+        _uomConverter = uomConverter;
         _invoices = invoices;
         _customers = customers;
         _items = items;
@@ -152,6 +154,12 @@ public sealed class SalesInvoiceService : ISalesInvoiceService
 
             var calc = _sales.ComputeLine(r.Qty, r.FreeQty, unitPrice, r.DiscountMode, r.DiscountPct, r.DiscountValue, r.DiscountAmount, r.TaxPct, r.IsFreeIssue);
 
+            // Resolve the base quantity now and store it on the line. This doubles as the
+            // entry-time UOM check (an item that cannot be sold in this UOM throws 422 here,
+            // while the user is still editing) and as the snapshot posting consumes — a
+            // conversion factor edited later must not change what this document posts.
+            var factor = await _uomConverter.ResolveFactorAsync(item, r.UomId, ct);
+
             lines.Add(new SalesInvoiceLine
             {
                 ItemId = r.ItemId,
@@ -159,6 +167,9 @@ public sealed class SalesInvoiceService : ISalesInvoiceService
                 Qty = r.Qty,
                 FreeQty = r.FreeQty,
                 UomId = r.UomId,
+                QtyBase = UomConverter.ApplyFactor(r.Qty, factor),
+                FreeQtyBase = UomConverter.ApplyFactor(r.FreeQty, factor),
+                ConversionFactor = factor,
                 WarehouseId = r.WarehouseId,
                 UnitPrice = unitPrice,
                 BaseCost = unitPrice,

Backend/ERPCore/Services/SalesPostingService.cs

@@ -23,6 +23,8 @@ public sealed class SalesPostingService : ISalesPostingService
     private readonly ICurrentUser _currentUser;
     private readonly IUnitOfWork _uow;
 
+    // No IUomConverter here by design: every line arrives with its base quantity already
+    // snapshotted by the service that saved it, so posting has nothing left to convert.
     public SalesPostingService(
         IRepository<SalesInvoice> invoices,
         IRepository<SalesSlip> slips,
@@ -57,18 +59,20 @@ public sealed class SalesPostingService : ISalesPostingService
         {
             if (!await _sales.IsStockedItemAsync(line.ItemId, ct))
                 continue;
-            var requestedQty = line.Qty + line.FreeQty;
+            // Compare base against base: on-hand is base UOM, so the entered quantity would
+            // under-report the requirement on any line not in the item's base UOM.
+            var requestedQty = line.QtyBase + line.FreeQtyBase;
             var available = await _fifo.GetOnHandAsync(line.ItemId, line.WarehouseId, ct);
             if (available >= requestedQty) continue;
 
             var item = await _items.Query().AsNoTracking()
                 .Where(x => x.ItemId == line.ItemId)
-                .Select(x => new { x.Sku, x.Name })
+                .Select(x => new { x.Sku, x.Name, BaseUomName = x.BaseUom!.Name })
                 .FirstAsync(ct);
 
             issues.Add(new SalesInvoicePostingIssueDto(
                 line.SalesInvoiceLineId, line.ItemId, item.Sku, item.Name, line.WarehouseId,
-                requestedQty, available, requestedQty - available, line.IsFreeIssue));
+                requestedQty, available, requestedQty - available, line.IsFreeIssue, item.BaseUomName));
         }
 
         return new SalesInvoicePostingCheckDto(invoice.SalesInvoiceId, invoice.InvoiceNo, invoice.Status, issues.Count == 0, issues);
@@ -88,18 +92,19 @@ public sealed class SalesPostingService : ISalesPostingService
         {
             if (!await _sales.IsStockedItemAsync(line.ItemId, ct))
                 continue;
-            var requestedQty = line.Qty + line.FreeQty;
+            // Base against base — see the matching comment in CheckInvoiceAsync.
+            var requestedQty = line.QtyBase + line.FreeQtyBase;
             var available = await _fifo.GetOnHandAsync(line.ItemId, line.WarehouseId, ct);
             if (available >= requestedQty) continue;
 
             var item = await _items.Query().AsNoTracking()
                 .Where(x => x.ItemId == line.ItemId)
-                .Select(x => new { x.Sku, x.Name })
+                .Select(x => new { x.Sku, x.Name, BaseUomName = x.BaseUom!.Name })
                 .FirstAsync(ct);
 
             issues.Add(new SalesSlipPostingIssueDto(
                 line.SalesSlipLineId, line.ItemId, item.Sku, item.Name, line.WarehouseId,
-                requestedQty, available, requestedQty - available, line.IsFreeIssue));
+                requestedQty, available, requestedQty - available, line.IsFreeIssue, item.BaseUomName));
         }
 
         return new SalesSlipPostingCheckDto(slip.SalesSlipId, slip.SlipNo, slip.Status, issues.Count == 0, issues);
@@ -119,15 +124,17 @@ public sealed class SalesPostingService : ISalesPostingService
         {
             if (!await _sales.IsStockedItemAsync(line.ItemId, ct))
                 continue;
-            var available = await _fifo.GetOnHandAsync(line.ItemId, line.WarehouseId, ct);
-            if (available >= line.Qty) continue;
 
             var item = await _items.Query().AsNoTracking()
                 .Where(x => x.ItemId == line.ItemId)
-                .Select(x => new { x.Sku, x.Name })
+                .Select(x => new { x.Sku, x.Name, BaseUomName = x.BaseUom!.Name })
                 .FirstAsync(ct);
+            var available = await _fifo.GetOnHandAsync(line.ItemId, line.WarehouseId, ct);
+            if (available >= line.QtyBase) continue;
 
-            issues.Add(new BundleSalePostingIssueDto(line.BundleSaleLineId, line.ItemId, item.Sku, item.Name, line.WarehouseId, line.Qty, available, line.Qty - available));
+            issues.Add(new BundleSalePostingIssueDto(
+                line.BundleSaleLineId, line.ItemId, item.Sku, item.Name, line.WarehouseId,
+                line.QtyBase, available, line.QtyBase - available, item.BaseUomName));
         }
 
         return new BundleSalePostingCheckDto(bundle.BundleSaleId, bundle.BundleNo, bundle.Status, issues.Count == 0, issues);
@@ -139,10 +146,10 @@ public sealed class SalesPostingService : ISalesPostingService
             notFoundMessage: $"Sales invoice {salesInvoiceId} was not found.",
             statusSelector: x => x.Status,
             ensureDraftMessage: x => $"Sales invoice {x.SalesInvoiceId} is {x.Status} and cannot be posted.",
-            getLines: x => x.Lines.Select(l => new PostingLine(l.ItemId, l.WarehouseId, l.Qty + l.FreeQty, l.Qty, l.FreeQty)),
+            getLines: x => x.Lines.Select(l => new PostingLine(l.ItemId, l.WarehouseId, l.QtyBase + l.FreeQtyBase, l.QtyBase, l.FreeQtyBase)),
             setPosted: x => x.Status = SalesInvoiceStatus.Posted,
             setUpdated: x => x.UpdatedAt = DateTime.UtcNow,
-            sourceDocType: nameof(SalesInvoice),
+            sourceDocType: DocumentTypes.SalesInvoice,
             getDocId: x => x.SalesInvoiceId,
             ct: ct);
 
@@ -152,10 +159,10 @@ public sealed class SalesPostingService : ISalesPostingService
             notFoundMessage: $"Sales slip {salesSlipId} was not found.",
             statusSelector: x => x.Status,
             ensureDraftMessage: x => $"Sales slip {x.SalesSlipId} is {x.Status} and cannot be posted.",
-            getLines: x => x.Lines.Select(l => new PostingLine(l.ItemId, l.WarehouseId, l.Qty + l.FreeQty, l.Qty, l.FreeQty)),
+            getLines: x => x.Lines.Select(l => new PostingLine(l.ItemId, l.WarehouseId, l.QtyBase + l.FreeQtyBase, l.QtyBase, l.FreeQtyBase)),
             setPosted: x => x.Status = SalesSlipStatus.Posted,
             setUpdated: x => x.UpdatedAt = DateTime.UtcNow,
-            sourceDocType: nameof(SalesSlip),
+            sourceDocType: DocumentTypes.SalesSlip,
             getDocId: x => x.SalesSlipId,
             ct: ct);
 
@@ -165,10 +172,10 @@ public sealed class SalesPostingService : ISalesPostingService
             notFoundMessage: $"Bundle sale {bundleSaleId} was not found.",
             statusSelector: x => x.Status,
             ensureDraftMessage: x => $"Bundle sale {x.BundleSaleId} is {x.Status} and cannot be posted.",
-            getLines: x => x.Lines.Where(l => l.IncludeInBundle).Select(l => new PostingLine(l.ItemId, l.WarehouseId, l.Qty, l.Qty, 0m)),
+            getLines: x => x.Lines.Where(l => l.IncludeInBundle).Select(l => new PostingLine(l.ItemId, l.WarehouseId, l.QtyBase, l.QtyBase, 0m)),
             setPosted: x => x.Status = BundleSaleStatus.Posted,
             setUpdated: x => x.UpdatedAt = DateTime.UtcNow,
-            sourceDocType: nameof(BundleSale),
+            sourceDocType: DocumentTypes.BundleSale,
             getDocId: x => x.BundleSaleId,
             ct: ct);
 
@@ -210,5 +217,11 @@ public sealed class SalesPostingService : ISalesPostingService
         }, ct);
     }
 
+    /// <summary>
+    /// A line reduced to what posting needs. Every quantity here is in the item's <b>base</b>
+    /// UOM, taken from the snapshot the document service resolved at save — the FIFO engine
+    /// accepts nothing else, and re-resolving at post time would let a factor edited in the
+    /// meantime change what a saved document consumes.
+    /// </summary>
     private sealed record PostingLine(int ItemId, int WarehouseId, decimal Qty, decimal PaidQty, decimal FreeQty);
 }

Backend/ERPCore/Services/SalesPromotionSuggestionService.cs

@@ -9,8 +9,6 @@ namespace ERPCore.Services;
 
 public sealed class SalesPromotionSuggestionService : ISalesPromotionSuggestionService
 {
-    private const decimal FreeIssueThreshold = 10m;
-
     private readonly IRepository<SalesSlip> _slips;
     private readonly IRepository<Item> _items;
 
@@ -27,7 +25,14 @@ public sealed class SalesPromotionSuggestionService : ISalesPromotionSuggestionS
 
         if (slip is null) return null;
 
-        var itemIds = slip.Lines.Select(x => x.ItemId).Distinct().ToList();
+        var freeIssueLines = slip.Lines
+            .Where(x => x.IsFreeIssue || x.FreeQty > 0m)
+            .ToList();
+
+        if (freeIssueLines.Count == 0)
+            return new SalesFreeIssueSuggestionDto(slip.SalesSlipId, slip.SlipNo, slip.SlipDate, Array.Empty<SalesFreeIssueSuggestionLineDto>());
+
+        var itemIds = freeIssueLines.Select(x => x.ItemId).Distinct().ToList();
         var candidateItems = await _items.Query().AsNoTracking()
             .Where(x => itemIds.Contains(x.ItemId) && x.Status == EntityStatus.Active)
             .ToListAsync(ct);
@@ -35,13 +40,10 @@ public sealed class SalesPromotionSuggestionService : ISalesPromotionSuggestionS
         var byItemId = candidateItems.ToDictionary(x => x.ItemId);
         var suggestions = new List<SalesFreeIssueSuggestionLineDto>();
 
-        foreach (var line in slip.Lines.Where(x => x.Qty >= FreeIssueThreshold))
+        foreach (var line in freeIssueLines)
         {
             if (!byItemId.TryGetValue(line.ItemId, out var item)) continue;
 
-            var freeQty = Math.Floor(line.Qty / FreeIssueThreshold);
-            if (freeQty <= 0m) continue;
-
             var rewardOptions = new List<SalesFreeIssueRewardOptionDto>
             {
                 new(item.ItemId, item.Sku, item.Name, item.SalePrice)
@@ -62,8 +64,8 @@ public sealed class SalesPromotionSuggestionService : ISalesPromotionSuggestionS
                 item.Sku,
                 item.Name,
                 line.Qty,
-                freeQty,
-                FreeIssueThreshold,
+                line.FreeQty,
+                line.Qty,
                 rewardOptions));
         }
 
@@ -71,4 +73,4 @@ public sealed class SalesPromotionSuggestionService : ISalesPromotionSuggestionS
             ? new SalesFreeIssueSuggestionDto(slip.SalesSlipId, slip.SlipNo, slip.SlipDate, Array.Empty<SalesFreeIssueSuggestionLineDto>())
             : new SalesFreeIssueSuggestionDto(slip.SalesSlipId, slip.SlipNo, slip.SlipDate, suggestions);
     }
-}
+}

Backend/ERPCore/Services/SalesSlipService.cs

@@ -26,6 +26,7 @@ public sealed class SalesSlipService : ISalesSlipService
     private readonly ISalesPostingService _posting;
     private readonly ISalesMappingService _mapping;
     private readonly ISalesDocumentWorkflowService _workflow;
+    private readonly IUomConverter _uomConverter;
     private readonly ICurrentUser _currentUser;
     private readonly INumberSequenceService _numbers;
     private readonly IUnitOfWork _uow;
@@ -33,9 +34,10 @@ public sealed class SalesSlipService : ISalesSlipService
     public SalesSlipService(
         IRepository<SalesSlip> slips, IRepository<Customer> customers, IRepository<Item> items,
         IRepository<Uom> uoms, IRepository<Warehouse> warehouses, IRepository<User> users, ISalesDomainService sales, ISalesPostingService posting, ISalesMappingService mapping,
-        ISalesDocumentWorkflowService workflow,
+        ISalesDocumentWorkflowService workflow, IUomConverter uomConverter,
         ICurrentUser currentUser, INumberSequenceService numbers, IUnitOfWork uow)
     {
+        _uomConverter = uomConverter;
         _slips = slips;
         _customers = customers;
         _items = items;
@@ -176,6 +178,10 @@ public sealed class SalesSlipService : ISalesSlipService
 
             var calc = _sales.ComputeLine(r.Qty, r.FreeQty, unitPrice, r.DiscountMode, r.DiscountPct, r.DiscountValue, r.DiscountAmount, r.TaxPct, r.IsFreeIssue);
 
+            // Resolve the base quantity now and store it on the line — see the matching
+            // comment in SalesInvoiceService.BuildLinesAsync.
+            var factor = await _uomConverter.ResolveFactorAsync(item, r.UomId, ct);
+
             lines.Add(new SalesSlipLine
             {
                 ItemId = r.ItemId,
@@ -183,6 +189,9 @@ public sealed class SalesSlipService : ISalesSlipService
                 Qty = r.Qty,
                 FreeQty = r.FreeQty,
                 UomId = r.UomId,
+                QtyBase = UomConverter.ApplyFactor(r.Qty, factor),
+                FreeQtyBase = UomConverter.ApplyFactor(r.FreeQty, factor),
+                ConversionFactor = factor,
                 WarehouseId = r.WarehouseId,
                 UnitPrice = unitPrice,
                 BaseCost = unitPrice,

Backend/ERPCore/Services/Stock/StockService.cs

@@ -14,17 +14,32 @@ public sealed class StockService : IStockService
     private readonly IRepository<StockLayer> _layers;
     private readonly IRepository<StockLedger> _ledger;
     private readonly IRepository<StockTransferLine> _transferLines;
+    private readonly IRepository<Item> _items;
 
     public StockService(
         IFifoCostingService fifo, IRepository<StockLayer> layers,
-        IRepository<StockLedger> ledger, IRepository<StockTransferLine> transferLines)
+        IRepository<StockLedger> ledger, IRepository<StockTransferLine> transferLines,
+        IRepository<Item> items)
     {
         _fifo = fifo;
         _layers = layers;
         _ledger = ledger;
         _transferLines = transferLines;
+        _items = items;
     }
 
+    /// <summary>
+    /// Base UOM (id + name) for a set of items, as one query. Stock reads are already
+    /// set-based to avoid N+1; this keeps the UOM label on the same footing.
+    /// </summary>
+    private async Task<Dictionary<int, (int Id, string Name)>> BaseUomsAsync(
+        IReadOnlyCollection<int> itemIds, CancellationToken ct)
+        => (await _items.Query().AsNoTracking()
+                .Where(i => itemIds.Contains(i.ItemId))
+                .Select(i => new { i.ItemId, i.BaseUomId, Name = i.BaseUom!.Name })
+                .ToListAsync(ct))
+            .ToDictionary(x => x.ItemId, x => (x.BaseUomId, x.Name));
+
     public async Task<StockOnHandDto> GetOnHandAsync(int itemId, int warehouseId, CancellationToken ct = default)
     {
         var onHand = await _fifo.GetOnHandAsync(itemId, warehouseId, ct);
@@ -47,7 +62,10 @@ public sealed class StockService : IStockService
         const decimal reserved = 0m;
         var available = onHand - onHold - reserved;
 
-        return new StockOnHandDto(itemId, warehouseId, onHand, available, onHold, inTransit, reserved, DateTime.UtcNow);
+        var uom = (await BaseUomsAsync([itemId], ct)).GetValueOrDefault(itemId);
+        return new StockOnHandDto(
+            itemId, warehouseId, onHand, available, onHold, inTransit, reserved, DateTime.UtcNow,
+            uom.Id, uom.Name ?? string.Empty);
     }
 
     /// <summary>
@@ -100,16 +118,20 @@ public sealed class StockService : IStockService
             .ToListAsync(ct))
             .ToDictionary(x => (x.ItemId, x.WarehouseId), x => x.Qty);
 
+        var baseUoms = await BaseUomsAsync(itemIds, ct);
+
         var asOf = DateTime.UtcNow;
         var rows = page.Select(p =>
         {
             var key = (p.ItemId, p.WarehouseId);
             var hold = onHold.GetValueOrDefault(key);
             var transit = inTransit.GetValueOrDefault(key);
+            var uom = baseUoms.GetValueOrDefault(p.ItemId);
             const decimal reserved = 0m;
             // Same formula as GetOnHandAsync: in-transit is reported, not re-subtracted.
             return new StockOnHandDto(
-                p.ItemId, p.WarehouseId, p.OnHand, p.OnHand - hold - reserved, hold, transit, reserved, asOf);
+                p.ItemId, p.WarehouseId, p.OnHand, p.OnHand - hold - reserved, hold, transit, reserved, asOf,
+                uom.Id, uom.Name ?? string.Empty);
         }).ToList();
 
         return PagedResponse<StockOnHandDto>.Create(rows, query.Page, query.PageSize, total);
@@ -139,9 +161,20 @@ public sealed class StockService : IStockService
                 l.SourceDocType, l.SourceDocId, l.UserId, l.CreatedAt))
             .ToListAsync(ct);
 
+        var baseUoms = await BaseUomsAsync(rows.Select(r => r.ItemId).Distinct().ToList(), ct);
+        rows = rows.Select(r =>
+        {
+            var uom = baseUoms.GetValueOrDefault(r.ItemId);
+            return r with { BaseUomId = uom.Id, BaseUomName = uom.Name ?? string.Empty };
+        }).ToList();
+
         return PagedResponse<StockLedgerRowDto>.Create(rows, query.Page, query.PageSize, total);
     }
 
-    public Task<StockValuationDto> GetValuationAsync(int itemId, int warehouseId, CancellationToken ct = default)
-        => _fifo.GetValuationAsync(itemId, warehouseId, ct);
+    public async Task<StockValuationDto> GetValuationAsync(int itemId, int warehouseId, CancellationToken ct = default)
+    {
+        var valuation = await _fifo.GetValuationAsync(itemId, warehouseId, ct);
+        var uom = (await BaseUomsAsync([itemId], ct)).GetValueOrDefault(itemId);
+        return valuation with { BaseUomId = uom.Id, BaseUomName = uom.Name ?? string.Empty };
+    }
 }

Backend/ERPCore/Services/Stock/UomConverter.cs

@@ -1,4 +1,5 @@
 using ERPCore.Domain.Entities;
+using ERPCore.Dtos.Uoms;
 using ERPCore.Repositories.Interfaces;
 using ERPCore.Services.Interfaces;
 using ERPCore.System.Errors;
@@ -11,28 +12,128 @@ namespace ERPCore.Services.Stock;
 /// unchanged from the <c>GrnService.ToBaseAsync</c> it was extracted from, so the GRN
 /// receive path keeps costing exactly as before.
 /// </summary>
+/// <remarks>
+/// Conversions are one-directional by design: a row always reads
+/// <c>FromUom → ToUom = item.BaseUomId</c>, enforced on write by
+/// <c>ItemService.UpdateUomConversionsAsync</c>. Nothing here inverts a factor, so a row
+/// stored in the opposite direction would be invisible to every caller — which is exactly
+/// why the write side rejects it rather than this side guessing.
+/// </remarks>
 public sealed class UomConverter : IUomConverter
 {
-    private readonly IRepository<UomConversion> _conversions;
+    /// <summary>Quantity columns are <c>(18,4)</c> across the model.</summary>
+    private const int QtyScale = 4;
 
-    public UomConverter(IRepository<UomConversion> conversions) => _conversions = conversions;
+    /// <summary>Unit-cost columns and <c>uom_conversions.Factor</c> are <c>(18,6)</c>.</summary>
+    private const int CostScale = 6;
+
+    private readonly IRepository<UomConversion> _conversions;
+    private readonly IRepository<Item> _items;
+    private readonly IRepository<Uom> _uoms;
+
+    public UomConverter(IRepository<UomConversion> conversions, IRepository<Item> items, IRepository<Uom> uoms)
+    {
+        _conversions = conversions;
+        _items = items;
+        _uoms = uoms;
+    }
 
     public async Task<(decimal QtyBase, decimal UnitCostBase)> ToBaseAsync(
         Item item, int uomId, decimal qty, decimal unitCostPerUom, CancellationToken ct = default)
     {
-        if (uomId == item.BaseUomId)
+        var factor = await ResolveFactorAsync(item, uomId, ct);
+        if (factor == 1m)
             return (qty, unitCostPerUom);
 
-        var conv = await _conversions.Query().AsNoTracking()
-            .FirstOrDefaultAsync(c => c.ItemId == item.ItemId && c.FromUomId == uomId && c.ToUomId == item.BaseUomId, ct)
-            ?? throw new DomainException(ErrorCodes.Validation,
-                $"No UOM conversion from {uomId} to base UOM {item.BaseUomId} for item {item.ItemId}.", 422);
-
         // Quantity scales up by the factor, so the per-unit cost scales down by it —
-        // total value is preserved.
-        return (qty * conv.Factor, unitCostPerUom / conv.Factor);
+        // total value is preserved. Round to each column's own scale here rather than
+        // letting the provider truncate on write, so what posts is what was computed.
+        return (
+            Math.Round(qty * factor, QtyScale, MidpointRounding.AwayFromZero),
+            Math.Round(unitCostPerUom / factor, CostScale, MidpointRounding.AwayFromZero));
     }
 
     public async Task<decimal> ToBaseQtyAsync(Item item, int uomId, decimal qty, CancellationToken ct = default)
         => (await ToBaseAsync(item, uomId, qty, 0m, ct)).QtyBase;
+
+    public async Task<decimal> ResolveFactorAsync(Item item, int uomId, CancellationToken ct = default)
+    {
+        if (uomId == item.BaseUomId)
+            return 1m;
+
+        var conv = await _conversions.Query().AsNoTracking()
+            .FirstOrDefaultAsync(c => c.ItemId == item.ItemId && c.FromUomId == uomId && c.ToUomId == item.BaseUomId, ct);
+
+        if (conv is null)
+            throw await NoConversionAsync(item, uomId, ct);
+
+        return conv.Factor;
+    }
+
+    public async Task<IReadOnlyList<AllowedUomDto>> GetAllowedUomsAsync(int itemId, CancellationToken ct = default)
+    {
+        var item = await _items.Query().AsNoTracking()
+            .Where(i => i.ItemId == itemId)
+            .Select(i => new { i.ItemId, i.BaseUomId, BaseUomName = i.BaseUom!.Name })
+            .FirstOrDefaultAsync(ct)
+            ?? throw new NotFoundException($"Item {itemId} was not found.");
+
+        var converted = await _conversions.Query().AsNoTracking()
+            .Where(c => c.ItemId == itemId && c.ToUomId == item.BaseUomId && c.FromUomId != item.BaseUomId)
+            .Select(c => new AllowedUomDto(c.FromUomId, c.FromUom!.Name, c.Factor, false))
+            .ToListAsync(ct);
+
+        // Base first — it is what every form defaults to — then the alternates by name.
+        return converted
+            .OrderBy(u => u.Name)
+            .Prepend(new AllowedUomDto(item.BaseUomId, item.BaseUomName, 1m, true))
+            .ToList();
+    }
+
+    public async Task ValidateUomAsync(Item item, int uomId, CancellationToken ct = default)
+    {
+        if (uomId == item.BaseUomId)
+            return;
+
+        var exists = await _conversions.Query().AsNoTracking()
+            .AnyAsync(c => c.ItemId == item.ItemId && c.FromUomId == uomId && c.ToUomId == item.BaseUomId, ct);
+
+        if (!exists)
+            throw await NoConversionAsync(item, uomId, ct);
+    }
+
+    /// <summary>
+    /// Applies an already-resolved factor to a quantity, rounded to the quantity scale.
+    /// Callers that snapshot a line use this so every base quantity in the system is
+    /// derived and rounded identically.
+    /// </summary>
+    public static decimal ApplyFactor(decimal qty, decimal factor)
+        => Math.Round(qty * factor, QtyScale, MidpointRounding.AwayFromZero);
+
+    /// <summary>
+    /// Restates a base quantity in <paramref name="factor"/>'s UOM. <b>Display only</b> —
+    /// this divides, so it can drift, and its result must never reach a stock or ledger
+    /// write. Conversion toward base is the authoritative direction.
+    /// </summary>
+    public static decimal FromBase(decimal qtyBase, decimal factor)
+        => factor == 0m ? 0m : Math.Round(qtyBase / factor, QtyScale, MidpointRounding.AwayFromZero);
+
+    /// <summary>
+    /// Builds the 422 for an unconvertible UOM. Names the units the item actually accepts,
+    /// because the bare id in the old message told the user nothing about how to recover.
+    /// </summary>
+    private async Task<DomainException> NoConversionAsync(Item item, int uomId, CancellationToken ct)
+    {
+        var attempted = await _uoms.Query().AsNoTracking()
+            .Where(u => u.UomId == uomId)
+            .Select(u => u.Name)
+            .FirstOrDefaultAsync(ct) ?? $"#{uomId}";
+
+        var allowed = await GetAllowedUomsAsync(item.ItemId, ct);
+
+        return new DomainException(ErrorCodes.Validation,
+            $"Item {item.Sku} cannot be transacted in {attempted}. Allowed units: " +
+            $"{string.Join(", ", allowed.Select(u => u.Name))}. " +
+            "Add a UOM conversion on the item to use another unit.", 422);
+    }
 }

Backend/ERPCore/appsettings.Development.json

@@ -6,7 +6,7 @@
     }
   },
   "ConnectionStrings": {
-    "DefaultConnection": "Host=localhost;Port=5432;Database=ERPCoreDev;Username=postgres;Password=root"
+    "DefaultConnection": "Host=127.0.0.1;Port=5433;Database=ERPCoreTest;Username=postgres;Password=post@hexdive"
   },
   "AuthHex": {
     "BaseUrl": "http://localhost:5011"

Backend/ERPCore/package-lock.json

@@ -0,0 +1,6 @@
+{
+  "name": "ERPCore",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {}
+}

Backend/smoke/run_all.py

@@ -25,6 +25,11 @@ SCRIPTS = [
     ("M4b UOM conversion on stock inputs", "m4b_uom_conversion.py"),
     ("M5  terminal receipt + cost pool", "m5_receipt.py"),
     ("M6+M7 leftover / rework / cancel", "m6_m7_leftover_rework_cancel.py"),
+    # UOM engine. These run after the manufacturing scripts because they reuse the
+    # SMOKE-PRD warehouse m4 creates, and they drain it before seeding their own stock.
+    ("UOM conversion direction is enforced", "uom_direction.py"),
+    ("UOM non-base sales consume converted qty", "uom_sales_nonbase.py"),
+    ("UOM cross-unit GRN against a PO", "uom_grn_po_cross.py"),
 ]
 
 SUMMARY = re.compile(r"^(\S+): (\d+)/(\d+) assertions passed")

Backend/smoke/uom_direction.py

@@ -0,0 +1,81 @@
+"""Smoke test — UOM conversions are one-directional, and the API says so.
+
+`UomConverter` looks up exactly one shape, `FromUom -> ToUom = item.BaseUomId`, and never
+inverts a factor. `UpdateUomConversionsAsync` used to accept *any* pair, so saving the more
+natural-reading `base -> BOX` produced a row that returned 200, appeared in the item detail
+response, and was then silently invisible to every consumer — surfacing much later as
+"no UOM conversion" 422 at GRN confirm or stage start, on an item that visibly had one.
+
+  * base -> other is rejected with 422 (the direction that used to save and then not work)
+  * other -> base is accepted
+  * a self-conversion and a base-as-source row are rejected
+  * a zero/negative factor is rejected (UomConverter divides unit cost by it)
+  * changing an item's base UOM while conversions exist is refused rather than orphaning them
+
+    python Backend/smoke/uom_direction.py
+"""
+
+from __future__ import annotations
+
+import sys
+
+from smoke_common import bootstrap
+
+
+def main():
+    c, chk, args = bootstrap(__doc__)
+    print(f"API {args.api}")
+
+    item = c.get("/items?pageSize=1&status=Active").body["items"]
+    if not item:
+        sys.exit("FATAL: no active items.")
+    item = item[0]
+    item_id, base_uom = item["itemId"], item["baseUomId"]
+
+    uoms = c.get("/uoms?pageSize=50").body["items"]
+    other = next((u["uomId"] for u in uoms if u["uomId"] != base_uom), None)
+    if other is None:
+        sys.exit("FATAL: need at least 2 UOMs.")
+    print(f"item={item_id} baseUom={base_uom} otherUom={other}")
+
+    def put(conversions):
+        return c.put(f"/items/{item_id}/uom-conversions", {"conversions": conversions})
+
+    chk.section("1. The correct direction is accepted")
+    ok = put([{"fromUom": other, "toUom": base_uom, "factor": 12}])
+    chk.status("other -> base", ok, 200)
+    if ok.status == 200:
+        chk.check("stored with the base UOM as target", ok.body["conversions"][0]["toUom"], base_uom)
+
+    chk.section("2. The reverse direction is rejected, not silently stored")
+    chk.status("base -> other", put([{"fromUom": base_uom, "toUom": other, "factor": 12}]), 422)
+
+    chk.section("3. Degenerate rows are rejected")
+    chk.status("self-conversion (other -> other)", put([{"fromUom": other, "toUom": other, "factor": 2}]), 422)
+    chk.status("zero factor", put([{"fromUom": other, "toUom": base_uom, "factor": 0}]), 422)
+    chk.status("negative factor", put([{"fromUom": other, "toUom": base_uom, "factor": -3}]), 422)
+
+    chk.section("4. Base UOM cannot be repointed while conversions exist")
+    # Restore a valid conversion first, so the guard has something to protect.
+    put([{"fromUom": other, "toUom": base_uom, "factor": 12}])
+    head = c.get(f"/items/{item_id}")
+    if head.status == 200:
+        body = head.body
+        moved = c.put(f"/items/{item_id}", {
+            "sku": body["sku"], "name": body["name"], "description": body.get("description"),
+            "categoryId": body["categoryId"], "subCategoryId": body.get("subCategoryId"),
+            "brandId": body.get("brandId"),
+            "baseUomId": other,                      # <- the repoint being guarded
+            "defaultVendorId": body.get("defaultVendorId"),
+            "stockNature": body["stockNature"], "trackingMode": body["trackingMode"],
+            "taxClass": body.get("taxClass"), "salePrice": body.get("salePrice"),
+        }, if_match=head.etag)
+        chk.status("change base UOM with conversions defined", moved, 422)
+    else:
+        chk.check("could read the item for the repoint test", head.status, 200)
+
+    return chk.finish("UOM-DIRECTION")
+
+
+if __name__ == "__main__":
+    sys.exit(main())

Backend/smoke/uom_grn_po_cross.py

@@ -0,0 +1,127 @@
+"""Smoke test — receiving in a different UOM from the one ordered.
+
+`GrnService` compared the GRN line's entered quantity against `poLine.Qty - poLine.QtyReceived`
+with no conversion, so a PO for 10 BOX receiving a legitimate 120 base units was rejected
+outright with OVER_RECEIPT_TOLERANCE — a user-visible false failure. It then accrued the GRN's
+quantity into `poLine.QtyReceived` (a PO-UOM field), and the close condition consumed that
+mixed-unit value, so a PO could close early or never close.
+
+Both sides now run on the base pair (`QtyBase` / `QtyReceivedBase`), with `QtyReceived` kept
+as a denormalized display figure only.
+
+  * a receipt in base UOM against a PO raised in BOX is ACCEPTED
+  * the FIFO layer and ledger record the base quantity
+  * `qtyReceivedBase` accrues correctly and the PO reaches FullyReceived
+  * over-receipt beyond tolerance is still rejected, now measured in base units
+
+    python Backend/smoke/uom_grn_po_cross.py
+"""
+
+from __future__ import annotations
+
+import sys
+
+from smoke_common import bootstrap, drain_stock, ensure_vendor
+
+WAREHOUSE_CODE = "SMOKE-PRD"
+FACTOR = 12
+ORDER_BOXES = 10          # -> 120 base units
+RECEIVE_BASE = 120        # the whole order, expressed in base units
+
+
+def main():
+    c, chk, args = bootstrap(__doc__)
+    print(f"API {args.api}")
+
+    wh = next((w["warehouseId"] for w in c.get(f"/warehouses?q={WAREHOUSE_CODE}&pageSize=50").body["items"]
+               if w["code"] == WAREHOUSE_CODE), None)
+    if wh is None:
+        sys.exit("FATAL: run m4_stage_actions.py first (it creates the SMOKE-PRD warehouse).")
+
+    item = next((i for i in c.get("/items?pageSize=20&status=Active").body["items"]
+                 if i["stockNature"] == "Stocked" and i["trackingMode"] == "None"), None)
+    if item is None:
+        sys.exit("FATAL: need a Stocked, untracked item.")
+    base_uom = item["baseUomId"]
+
+    uoms = c.get("/uoms?pageSize=50").body["items"]
+    box_uom = next((u["uomId"] for u in uoms if u["uomId"] != base_uom), None)
+    if box_uom is None:
+        sys.exit("FATAL: need at least 2 UOMs.")
+
+    vendor = ensure_vendor(c)
+    print(f"item={item['itemId']} baseUom={base_uom} boxUom={box_uom} factor={FACTOR}")
+
+    chk.section("1. Conversion + a PO raised in BOX")
+    conv = c.put(f"/items/{item['itemId']}/uom-conversions",
+                 {"conversions": [{"fromUom": box_uom, "toUom": base_uom, "factor": FACTOR}]})
+    chk.status("define BOX -> base conversion", conv, 200)
+    if conv.status != 200:
+        return chk.finish("UOM-GRN-PO")
+
+    po = c.post("/purchase-orders", {
+        "vendorId": vendor,
+        "lines": [{"itemId": item["itemId"], "uomId": box_uom, "warehouseId": wh,
+                   "qty": ORDER_BOXES, "unitPrice": 60, "tax": 0}],
+    })
+    chk.status("create the PO in BOX", po, 201)
+    if po.status != 201:
+        return chk.finish("UOM-GRN-PO")
+
+    po_line = po.body["lines"][0]
+    chk.check("PO line keeps the ordered qty in BOX", float(po_line["qty"]), float(ORDER_BOXES))
+    chk.check("PO line snapshots the base quantity", float(po_line["qtyBase"]), float(ORDER_BOXES * FACTOR))
+    chk.check("PO line snapshots the factor", float(po_line["conversionFactor"]), float(FACTOR))
+
+    drain_stock(c, wh)
+    before = float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"])
+
+    chk.section("2. Receiving the order in BASE units is accepted")
+    grn = c.post("/grns", {
+        "vendorId": vendor, "warehouseId": wh, "poId": po.body["poId"],
+        "lines": [{"poLineId": po_line["poLineId"], "itemId": item["itemId"],
+                   "uomId": base_uom,                       # <- different UOM from the PO
+                   "qty": RECEIVE_BASE, "unitCost": 5, "discountPct": 0, "vatPct": 0}],
+    })
+    # This is the assertion that fails on the old code: it returned 422 OVER_RECEIPT_TOLERANCE.
+    chk.status("GRN in base UOM against a BOX purchase order", grn, 201)
+    if grn.status != 201:
+        return chk.finish("UOM-GRN-PO")
+
+    confirmed = c.post(f"/grns/{grn.body['grnId']}/confirm")
+    chk.status("confirm the GRN", confirmed, 200)
+    if confirmed.status != 200:
+        return chk.finish("UOM-GRN-PO")
+
+    chk.check("on-hand rose by the base quantity",
+              float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"]),
+              before + RECEIVE_BASE)
+
+    rows = c.get(f"/stock/ledger?sourceDocType=GRN&sourceDocId={grn.body['grnId']}&pageSize=50").body["items"]
+    chk.check("one GRN ledger row", len(rows), 1)
+    if rows:
+        chk.check("ledger qtyBase is the received base quantity", float(rows[0]["qtyBase"]), float(RECEIVE_BASE))
+
+    chk.section("3. The PO closes on the base pair")
+    reread = c.get(f"/purchase-orders/{po.body['poId']}")
+    chk.status("re-read the PO", reread, 200)
+    if reread.status == 200:
+        rl = reread.body["lines"][0]
+        chk.check("qtyReceivedBase accrued in base units", float(rl["qtyReceivedBase"]), float(RECEIVE_BASE))
+        chk.check("qtyReceived shown back in the PO's own UOM", float(rl["qtyReceived"]), float(ORDER_BOXES))
+        chk.check("PO is FullyReceived", reread.body["status"], "FullyReceived")
+
+    chk.section("4. Over-receipt is still rejected, measured in base")
+    over = c.post("/grns", {
+        "vendorId": vendor, "warehouseId": wh, "poId": po.body["poId"],
+        "lines": [{"poLineId": po_line["poLineId"], "itemId": item["itemId"],
+                   "uomId": base_uom, "qty": RECEIVE_BASE, "unitCost": 5,
+                   "discountPct": 0, "vatPct": 0}],
+    })
+    chk.status("receiving the whole order again", over, 422, "OVER_RECEIPT_TOLERANCE")
+
+    return chk.finish("UOM-GRN-PO")
+
+
+if __name__ == "__main__":
+    sys.exit(main())

Backend/smoke/uom_sales_nonbase.py

@@ -0,0 +1,200 @@
+"""Smoke test — selling in a non-base UOM consumes the converted quantity.
+
+This is the regression test for the UOM engine's worst defect. `SalesPostingService`
+injected `IUomConverter` and never called it: `PostAsync` fed the *entered* line quantity
+straight into `IFifoCostingService.ConsumeAsync`, whose contract is base UOM only. Selling
+2 BOX of a 12-per-box item therefore removed 2 base units instead of 24 and wrote
+`StockLedger.QtyBase = 2` into a column defined as base — overstating stock, understating
+COGS, and drifting the ledger's running balance away from the layer sum.
+
+`m4b_uom_conversion.py` covered exactly the same hazard on the *production* path, which is
+why that path was correct and this one was not. This script closes the gap:
+
+  * an invoice line in a non-base UOM consumes qty x factor base units
+  * the ledger records the BASE quantity
+  * the line still reports the ENTERED qty and UOM, so the printed document says "2 BOX"
+  * the pre-post check reports the shortfall in base units (it compared entered vs base
+    on-hand before, and answered "can post" when it could not)
+  * the same holds for a sales slip, which shares PostAsync
+  * a UOM the item has no conversion for is refused at line creation, not at post
+
+    python Backend/smoke/uom_sales_nonbase.py
+"""
+
+from __future__ import annotations
+
+import sys
+
+from smoke_common import bootstrap, drain_stock, seed_costed_stock
+
+WAREHOUSE_CODE = "SMOKE-PRD"
+FACTOR = 12      # 1 BOX = 12 base units
+SELL_BOXES = 2   # -> 24 base units
+SEED_BASE = 100  # base units on hand before selling
+UNIT_COST = 5.0
+
+
+def main():
+    c, chk, args = bootstrap(__doc__)
+    print(f"API {args.api}")
+
+    wh = next((w["warehouseId"] for w in c.get(f"/warehouses?q={WAREHOUSE_CODE}&pageSize=50").body["items"]
+               if w["code"] == WAREHOUSE_CODE), None)
+    if wh is None:
+        sys.exit("FATAL: run m4_stage_actions.py first (it creates the SMOKE-PRD warehouse).")
+
+    item = next((i for i in c.get("/items?pageSize=20&status=Active").body["items"]
+                 if i["stockNature"] == "Stocked"), None)
+    if item is None:
+        sys.exit("FATAL: need a Stocked item.")
+    base_uom = item["baseUomId"]
+
+    uoms = c.get("/uoms?pageSize=50").body["items"]
+    box_uom = next((u["uomId"] for u in uoms if u["uomId"] != base_uom), None)
+    if box_uom is None:
+        sys.exit("FATAL: need at least 2 UOMs to test conversion.")
+
+    customer = c.get("/customers?pageSize=1").body["items"]
+    if not customer:
+        sys.exit("FATAL: no customers seeded.")
+    customer_id = customer[0]["customerId"]
+
+    print(f"item={item['itemId']} baseUom={base_uom} boxUom={box_uom} factor={FACTOR}")
+
+    # --- fixtures ---------------------------------------------------------
+    chk.section("1. Conversion + known on-hand")
+    conv = c.put(f"/items/{item['itemId']}/uom-conversions",
+                 {"conversions": [{"fromUom": box_uom, "toUom": base_uom, "factor": FACTOR}]})
+    chk.status("define BOX -> base conversion", conv, 200)
+    if conv.status != 200:
+        return chk.finish("UOM-SALES")
+
+    allowed = c.get(f"/items/{item['itemId']}/uoms")
+    chk.status("GET /items/{id}/uoms", allowed, 200)
+    if allowed.status == 200:
+        ids = [u["uomId"] for u in allowed.body]
+        chk.check("allowed UOMs are base + the conversion source", sorted(ids), sorted([base_uom, box_uom]))
+        chk.check("base UOM is flagged and listed first", allowed.body[0]["isBase"], True)
+
+    drain_stock(c, wh)
+    seed_costed_stock(c, wh, [(item["itemId"], base_uom, SEED_BASE, UNIT_COST)])
+    before = float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"])
+    chk.check(f"on-hand seeded to {SEED_BASE} base units", before, float(SEED_BASE))
+
+    on_hand = c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body
+    chk.check("stock read is labelled with the base UOM", on_hand["baseUomId"], base_uom)
+    chk.check("stock read carries the base UOM name", bool(on_hand["baseUomName"]), True)
+
+    # --- invoice in BOX ---------------------------------------------------
+    chk.section("2. An invoice line entered in BOX")
+    expected_base = SELL_BOXES * FACTOR   # 2 x 12 = 24
+
+    inv = c.post("/sales-invoices", {
+        "customerId": customer_id,
+        "warehouseId": wh,
+        "invoiceType": "B2C",
+        "lines": [{
+            "itemId": item["itemId"], "uomId": box_uom, "warehouseId": wh,
+            "qty": SELL_BOXES, "freeQty": 0, "unitPrice": 100, "allowManualPriceOverride": True,
+            "discountMode": "Percentage", "discountPct": 0, "discountAmount": 0,
+            "discountValue": 0, "taxPct": 0, "isFreeIssue": False,
+        }],
+    })
+    chk.status("create the invoice", inv, 201)
+    if inv.status != 201:
+        return chk.finish("UOM-SALES")
+
+    line = inv.body["lines"][0]
+    chk.check("line keeps the ENTERED qty (prints as 2 BOX)", float(line["qty"]), float(SELL_BOXES))
+    chk.check("line keeps the ENTERED uom", line["uomId"], box_uom)
+
+    check = c.get(f"/sales-invoices/{inv.body['salesInvoiceId']}/posting-check")
+    chk.status("posting check", check, 200)
+    if check.status == 200:
+        chk.check("posting check passes with enough stock", check.body["canPost"], True)
+
+    chk.section("3. Posting consumes the CONVERTED quantity")
+    posted = c.post(f"/sales-invoices/{inv.body['salesInvoiceId']}/post")
+    chk.status("post the invoice", posted, 200)
+    if posted.status != 200:
+        return chk.finish("UOM-SALES")
+
+    after = float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"])
+    chk.check(f"on-hand fell by {expected_base} base units, not {SELL_BOXES}", after, before - expected_base)
+
+    rows = c.get(f"/stock/ledger?sourceDocType=SINV&sourceDocId={inv.body['salesInvoiceId']}&pageSize=50").body["items"]
+    chk.check("one ledger row for the invoice", len(rows), 1)
+    if rows:
+        chk.check("ledger qtyBase is the CONVERTED quantity", float(rows[0]["qtyBase"]), float(expected_base))
+        chk.check("ledger row is labelled with the base UOM", rows[0]["baseUomId"], base_uom)
+
+    # --- the same on a slip ----------------------------------------------
+    chk.section("4. A sales slip behaves identically (shared PostAsync)")
+    before_slip = float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"])
+    slip = c.post("/sales-slips", {
+        "customerId": customer_id,
+        "warehouseId": wh,
+        "lines": [{
+            "itemId": item["itemId"], "uomId": box_uom, "warehouseId": wh,
+            "qty": SELL_BOXES, "freeQty": 0, "unitPrice": 100, "allowManualPriceOverride": True,
+            "discountMode": "Percentage", "discountPct": 0, "discountAmount": 0,
+            "discountValue": 0, "taxPct": 0, "isFreeIssue": False,
+        }],
+    })
+    chk.status("create the slip", slip, 201)
+    if slip.status == 201:
+        chk.status("post the slip", c.post(f"/sales-slips/{slip.body['salesSlipId']}/post"), 200)
+        chk.check("slip also consumed the converted quantity",
+                  float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"]),
+                  before_slip - expected_base)
+
+    # --- snapshot immutability -------------------------------------------
+    chk.section("5. A factor edited after save does not change what posts")
+    draft = c.post("/sales-invoices", {
+        "customerId": customer_id, "warehouseId": wh, "invoiceType": "B2C",
+        "lines": [{
+            "itemId": item["itemId"], "uomId": box_uom, "warehouseId": wh,
+            "qty": 1, "freeQty": 0, "unitPrice": 100, "allowManualPriceOverride": True,
+            "discountMode": "Percentage", "discountPct": 0, "discountAmount": 0,
+            "discountValue": 0, "taxPct": 0, "isFreeIssue": False,
+        }],
+    })
+    if draft.status == 201:
+        # Double the factor *after* the draft is saved.
+        c.put(f"/items/{item['itemId']}/uom-conversions",
+              {"conversions": [{"fromUom": box_uom, "toUom": base_uom, "factor": FACTOR * 2}]})
+        before_snap = float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"])
+        chk.status("post the pre-existing draft", c.post(f"/sales-invoices/{draft.body['salesInvoiceId']}/post"), 200)
+        chk.check(f"posted the snapshotted {FACTOR}, not the edited {FACTOR * 2}",
+                  float(c.get(f"/stock/on-hand?itemId={item['itemId']}&warehouseId={wh}").body["onHand"]),
+                  before_snap - FACTOR)
+        # Restore for re-runnability.
+        c.put(f"/items/{item['itemId']}/uom-conversions",
+              {"conversions": [{"fromUom": box_uom, "toUom": base_uom, "factor": FACTOR}]})
+    else:
+        chk.check("could create the snapshot-test draft", draft.status, 201)
+
+    # --- unusable UOM refused at entry ------------------------------------
+    chk.section("6. A UOM with no conversion is refused at line creation")
+    third = next((u["uomId"] for u in c.get("/uoms?pageSize=50").body["items"]
+                  if u["uomId"] not in (base_uom, box_uom)), None)
+    if third is None:
+        chk.check("skipped: need a third UOM", True, True)
+    else:
+        bad = c.post("/sales-invoices", {
+            "customerId": customer_id, "warehouseId": wh, "invoiceType": "B2C",
+            "lines": [{
+                "itemId": item["itemId"], "uomId": third, "warehouseId": wh,
+                "qty": 1, "freeQty": 0, "unitPrice": 100, "allowManualPriceOverride": True,
+                "discountMode": "Percentage", "discountPct": 0, "discountAmount": 0,
+                "discountValue": 0, "taxPct": 0, "isFreeIssue": False,
+            }],
+        })
+        # The point is that this fails at CREATE (while the user is editing), not at post.
+        chk.status("invoice line in an unconvertible UOM", bad, 422)
+
+    return chk.finish("UOM-SALES")
+
+
+if __name__ == "__main__":
+    sys.exit(main())

Frontend/PROGRESS.md

@@ -129,6 +129,8 @@ Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit**
 > **Fields not explicitly spelled out verbatim in GL's reference** (its own numeric-id column names for `ChequeBook`/`ChequePage`, and `ReceivedCheque`'s JSON id field) are built from the request-body field names GL *does* document plus this project's consistent `<entity>Id` convention, flagged in `types/general-ledger.ts`'s comments — `chequeNo`/`chequeBookNo` (both explicitly documented as the identifying route values) are used for keys/URLs throughout instead, sidestepping the guess entirely wherever possible. **Not done:** live smoke test against a running GL instance — this entire module is unverified against real Cheque Management data. Verified: `tsc --noEmit`/`eslint` clean on every touched file; `npm run build` compiles successfully (Turbopack), its full-project TypeScript check still blocked only by the pre-existing, unrelated `hrm/employees/[id]` error.
 >
 > **2026-07-20 (3) — General Ledger report corrected again: `accountId` dropped entirely, not just made direct-entry.** The GL service's own contract changed (confirmed against its updated docs): `GeneralLedger`'s `accountId` is now optional, and the *omitted* case is the real General Ledger (every postable account together, each with its own running balance, sorted by `accountCode` then `entryDate`) — supplying `accountId` is a separate "Account Ledger" (single account + descendants) mode this page doesn't use. Superseding the same-day entry above: the numeric Account ID input is gone, `reportsApi.generalLedger()` dropped the `accountId` parameter, and the page now fetches on `periodStart`/`periodEnd` alone with sensible defaults — auto-fetching on page load like every other report screen (this also resolves the earlier-reported "no network call when landing on the page," which was the now-removed account-required gate). Result rows are grouped into per-account sections in the table (a header row wherever `accountCode` changes), matching the API's per-account running-balance reset. No frontend change was needed for the same-day `BalanceSheet` response addition (a synthetic `"Current Year Earnings"` equity row) — the existing generic row renderer already displays whatever rows come back. Verified: `tsc --noEmit` clean, `npx eslint app/dashboard/ledgers lib/api/general-ledger.ts` produces zero output, `npm run build` succeeds.
+>
+> **2026-08-05 — Cheque Management status/type fields were rendering as raw integers, not names (user-reported + confirmed with GL's own `06_Enums_Reference.md`).** That doc's key fact: GL has no global `JsonStringEnumConverter`. A JSON-**body** enum field (e.g. the Issue-cheque form's `payeeType`) is independently declared `string` server-side and parsed via `Enum.TryParse`, and a query-string enum filter binds natively by name — both already correct here, unaffected. But `ChequeBook.status`, `ChequePage.issueStatus`, `ChequePage.payeeType`, `ReceivedCheque.receivedFromType`, and `ReceivedCheque.status` are genuine enum-typed properties on GL's own **response** DTOs, backed by real `integer` DB columns — with no converter, GL's JSON serializes each one as its raw number (`1`/`2`/`3`/...), not its name. This wasn't just a cosmetic label bug: every list badge, the dialogs' status-based available-actions logic, and any `===` comparison against this frontend's own string enums (`ChequeBookStatus.Active`, etc.) would have silently mismatched against these numbers. Fixed at the API boundary, not scattered across every consumer: added five `*_BY_CODE` lookup maps to `types/general-ledger.ts` (one per affected field, keyed by the exact integers `06_Enums_Reference.md` documents), and applied them in `lib/api/general-ledger.ts` via new `Raw*` types (describing GL's actual `number`/`number | null` response shape for these fields) plus `mapChequeBook`/`mapChequePage`/`mapReceivedCheque` helpers wired into every `chequeBooksApi`/`chequePagesApi`/`receivedChequesApi` method that returns one — so every page/dialog/badge map keeps working against the same string values as before, unchanged. Cross-checked every other enum in that doc's "Persisted enums" table against this frontend (`JournalEntryStatus`/`PeriodStatus`/`TaxCalculationBasis`/`TaxAppliesTo`/`DepreciationMethod`/`FixedAssetStatus`/`AuditCategory`/`AuditAction`) — none are consumed anywhere in this app, confirming Cheque Management was the complete fix, not a partial one. Verified: `tsc --noEmit`/`eslint` clean on both touched files.
 
 ## 7. UX states
 - [~] Loading / empty / error states on every list — done for the GRN list/create/detail screens; other screens still unbuilt

Frontend/erp-system/app/dashboard/hrm/employees/[id]/page.tsx

@@ -170,6 +170,7 @@ export default function EmployeeDetailPage() {
         emergencyContactName: employee.emergencyContactName,
         emergencyContactRelationship: employee.emergencyContactRelationship,
         emergencyContactPhone: employee.emergencyContactPhone,
+        hireDate: employee.hireDate,
         confirmationDate: employee.confirmationDate,
         lastWorkingDate: employee.lastWorkingDate,
         departmentId: employee.departmentId,

Frontend/erp-system/app/dashboard/procurement/purchase-orders/[id]/page.tsx

@@ -7,6 +7,7 @@ import { AlertTriangle, ArrowLeft, Ban, Check, Plus, Save, Trash2 } from "lucide
 import { isPoEditable, purchaseOrdersApi } from "@/lib/api/purchase-orders"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { itemsApi } from "@/lib/api/items"
+import { uomName } from "@/lib/uom"
 import { uomsApi } from "@/lib/api/uoms"
 import { vendorsApi } from "@/lib/api/vendors"
 import { errorMessage } from "@/lib/error-map"
@@ -111,8 +112,8 @@ export default function PurchaseOrderDetailPage() {
   function itemFor(itemId: number | null) {
     return items.find((i) => i.itemId === itemId) ?? null
   }
-  function uomName(uomId: number) {
-    return uoms.find((u) => u.uomId === uomId)?.name ?? `#${uomId}`
+  function uomLabel(uomId: number) {
+    return uomName(uomId, uoms)
   }
   function warehouseCode(warehouseId: number) {
     return warehouses.find((w) => w.warehouseId === warehouseId)?.code ?? `#${warehouseId}`
@@ -195,11 +196,9 @@ export default function PurchaseOrderDetailPage() {
       setPo(updated)
       setLines(toDraftLines(updated))
       toast.success("Purchase order approved", `${updated.docNo} — now ${updated.status} and locked for editing.`)
-      toast.success("Purchase order approved", `${updated.docNo} — now ${updated.status} and locked for editing.`)
     } catch (err) {
       setSaveError(errorMessage(err))
       toast.error("Could not approve purchase order", errorMessage(err))
-      toast.error("Could not approve purchase order", errorMessage(err))
     } finally {
       setSubmitting(false)
     }
@@ -286,10 +285,7 @@ export default function PurchaseOrderDetailPage() {
             <>
               <Button variant="success" size="lg" onClick={handleSubmitPo} disabled={submitting || deleting}>
                 <Check className="size-5" />
-                {submitting ? "Approving…" : "Approve"}
-              <Button variant="success" size="lg" onClick={handleSubmitPo} disabled={submitting || deleting}>
-                <Check className="size-5" />
-                {submitting ? "Approving…" : "Approve"}
+                {submitting ? "Approving�" : "Approve"}
               </Button>
               <Button variant="destructive" size="lg" onClick={handleDelete} disabled={deleting || submitting}>
                 <Trash2 className="size-5" />
@@ -381,7 +377,7 @@ export default function PurchaseOrderDetailPage() {
                   return (
                     <TableRow key={line.key}>
                       <TableCell className="px-3 py-3.5">{item ? `${item.sku} — ${item.name}` : `Item #${line.itemId}`}</TableCell>
-                      <TableCell className="px-3 py-3.5">{line.uomId ? uomName(line.uomId) : "—"}</TableCell>
+                      <TableCell className="px-3 py-3.5">{line.uomId ? uomLabel(line.uomId) : "—"}</TableCell>
                       <TableCell className="px-3 py-3.5">{line.warehouseId ? warehouseCode(line.warehouseId) : "—"}</TableCell>
                       <TableCell className="px-3 py-3.5">{line.qty}</TableCell>
                       <TableCell className="px-3 py-3.5">{line.qtyReceived}</TableCell>

Frontend/erp-system/app/dashboard/procurement/purchase-orders/new/page.tsx

@@ -14,6 +14,8 @@ import { itemsApi } from "@/lib/api/items"
 import { uomsApi } from "@/lib/api/uoms"
 import { errorMessage } from "@/lib/error-map"
 import { validatePoLine } from "@/lib/validations/procurement"
+import { pickerOptions } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { cn } from "@/lib/utils"
 import { generateVendorCode } from "@/lib/vendor-code"
 import { CreatePoLineInput } from "@/types/procurement"
@@ -52,10 +54,10 @@ function newKey() {
   return `poline-${keySeq}`
 }
 
-// Unit price and tax are no longer entered at PO creation — pricing is captured at GRN
-// receipt (with discount/VAT there). They default to 0 here and stay off the form, but
-// remain on the payload because the backend line DTO still requires them; a PO prefilled
-// from an RFQ keeps its negotiated price (below).
+// Tax is still not entered at PO creation — it's captured at GRN receipt (with discount/VAT
+// there) and stays off this form, though it remains on the payload since the backend line
+// DTO still requires it. Unit price *is* entered here; a PO prefilled from an RFQ starts
+// from its negotiated price (below) but stays editable.
 function emptyLine(): DraftLine {
   return { key: newKey(), itemId: null, uomId: null, warehouseId: null, qty: "", unitPrice: "0", tax: "0" }
 }
@@ -81,6 +83,7 @@ function NewPurchaseOrderContent() {
   const [lineErrors, setLineErrors] = useState<Record<string, Record<string, string>>>({})
   const [submitError, setSubmitError] = useState<string | null>(null)
   const [submitting, setSubmitting] = useState(false)
+  const allowedUoms = useAllowedUoms()
 
   const [vendorDialogOpen, setVendorDialogOpen] = useState(false)
   const [vName, setVName] = useState("")
@@ -102,7 +105,8 @@ function NewPurchaseOrderContent() {
   useEffect(() => {
     Promise.all([
       loadItems(),
-      uomsApi.list().then((uo) => setUoms(uo.items)),
+      // pageSize: the default page would silently truncate the unit list as the master grows.
+      uomsApi.list({ pageSize: 200 }).then((uo) => setUoms(uo.items)),
       warehousesApi.list().then((wh) => setWarehouses(wh.items)),
       loadVendors(),
     ]).catch((err) => setLoadError(errorMessage(err)))
@@ -306,7 +310,7 @@ function NewPurchaseOrderContent() {
       {!loading && (
         <>
           <div className="grid grid-cols-1 gap-4 sm:grid-cols-4">
-            <div className="flex flex-col gap-2 sm:col-span-2">
+            <div className="flex flex-col gap-2 sm:col-span-1">
               <Label className="text-base">Vendor</Label>
               <div className="flex items-center gap-2">
                 <Select<number | null>
@@ -406,13 +410,14 @@ function NewPurchaseOrderContent() {
 
             {lines.length > 0 && (
               <div className="overflow-x-auto">
-                <Table className="text-base">
+                <Table className="table-fixed text-base">
                   <TableHeader>
                     <TableRow>
-                      <TableHead className="h-12 w-56 px-3 text-sm">Item</TableHead>
-                      <TableHead className="h-12 w-28 px-3 text-sm">UOM</TableHead>
-                      <TableHead className="h-12 w-40 px-3 text-sm">Warehouse</TableHead>
+                      <TableHead className="h-12 w-32 px-3 text-sm">Item</TableHead>
+                      <TableHead className="h-12 w-16 px-3 text-sm">UOM</TableHead>
+                      <TableHead className="h-12 w-20 px-3 text-sm">Warehouse</TableHead>
                       <TableHead className="h-12 w-24 px-3 text-sm">Qty</TableHead>
+                      <TableHead className="h-12 w-28 px-3 text-sm">Unit price</TableHead>
                       <TableHead className="h-12 w-10 px-3" />
                     </TableRow>
                   </TableHeader>
@@ -424,11 +429,25 @@ function NewPurchaseOrderContent() {
                         <TableRow key={line.key}>
                           <TableCell className="px-3 py-3 align-top">
                             {requisitionId || rfqId ? (
-                              <div className="flex h-11 items-center text-base">{item ? `${item.sku} — ${item.name}` : `Item #${line.itemId}`}</div>
+                              <div className="flex h-11 items-center truncate text-base" title={item ? `${item.sku} — ${item.name}` : undefined}>{item ? `${item.sku} — ${item.name}` : `Item #${line.itemId}`}</div>
                             ) : (
                               <>
-                                <Select<number | null> value={line.itemId} onValueChange={(v) => updateLine(line.key, { itemId: v })}>
-                                  <SelectTrigger className="h-11! w-full text-base" aria-invalid={!!errors.itemId}>
+                                <Select<number | null>
+                                  value={line.itemId}
+                                  onValueChange={(v) => {
+                                    // Reset to the item's base unit and load its allowed units.
+                                    allowedUoms.load(v)
+                                    updateLine(line.key, {
+                                      itemId: v,
+                                      uomId: (items ?? []).find((i) => i.itemId === v)?.baseUomId ?? null,
+                                    })
+                                  }}
+                                >
+                                  <SelectTrigger
+                                    className="h-11! w-full text-base"
+                                    aria-invalid={!!errors.itemId}
+                                    title={item ? `${item.sku} — ${item.name}` : undefined}
+                                  >
                                     <SelectValue placeholder="Select item" />
                                   </SelectTrigger>
                                   <SelectContent>
@@ -449,7 +468,7 @@ function NewPurchaseOrderContent() {
                                 <SelectValue placeholder="UOM" />
                               </SelectTrigger>
                               <SelectContent>
-                                {(uoms ?? []).map((u) => (
+                                {pickerOptions(allowedUoms.get(line.itemId), uoms ?? []).map((u) => (
                                   <SelectItem key={u.uomId} value={u.uomId} className="text-base">
                                     {u.name}
                                   </SelectItem>
@@ -485,6 +504,18 @@ function NewPurchaseOrderContent() {
                             />
                             <FieldError errors={[errors.qty ? { message: errors.qty } : undefined]} />
                           </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Input
+                              type="number"
+                              min="0"
+                              step="any"
+                              value={line.unitPrice}
+                              aria-invalid={!!errors.unitPrice}
+                              onChange={(e) => updateLine(line.key, { unitPrice: e.target.value })}
+                              className="h-11 text-base"
+                            />
+                            <FieldError errors={[errors.unitPrice ? { message: errors.unitPrice } : undefined]} />
+                          </TableCell>
                           <TableCell className="px-3 py-3 align-top">
                             <Button type="button" variant="ghost" size="icon" onClick={() => removeLine(line.key)} aria-label="Remove line">
                               <Trash2 className="size-5" />

Frontend/erp-system/app/dashboard/production/templates/[id]/StageEditorPanel.tsx

@@ -3,6 +3,8 @@
 import { Plus, Trash2 } from "lucide-react"
 
 import { cn } from "@/lib/utils"
+import { pickerOptions } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { CustomFieldType, StageInputSource } from "@/types/production"
 import { ItemListItem, Uom } from "@/types/master-data"
 import {
@@ -46,7 +48,8 @@ function QtyRow({
 }: {
   qty: number
   uomId: number | null
-  uoms: Uom[]
+  /** Already narrowed to the row's item by the caller — see `pickerOptions`. */
+  uoms: { uomId: number; name: string }[]
   readOnly: boolean
   onQtyChange: (qty: number) => void
   onUomChange: (uomId: number) => void
@@ -125,9 +128,12 @@ export function StageEditorPanel({
     updateInput(localId, source === "Stock" ? { source, fromOutputKey: null } : { source, itemId: null })
   }
 
+  const allowedUoms = useAllowedUoms()
+
   /** Default the UOM to the item's base unit — right most of the time, still overridable. */
   function pickInputItem(input: BuilderInput, itemId: number) {
     const item = items.find((i) => i.itemId === itemId)
+    allowedUoms.load(itemId)
     updateInput(input.localId, { itemId, uomId: input.uomId ?? item?.baseUomId ?? null })
   }
 
@@ -146,6 +152,7 @@ export function StageEditorPanel({
   /** The terminal output's name mirrors the finished item, so the two can't drift apart. */
   function pickOutputItem(output: BuilderOutput, itemId: number) {
     const item = items.find((i) => i.itemId === itemId)
+    allowedUoms.load(itemId)
     updateOutput(output.key, {
       itemId,
       name: item?.name ?? output.name,
@@ -288,7 +295,7 @@ export function StageEditorPanel({
                     <QtyRow
                       qty={input.qtyPerBatch}
                       uomId={input.uomId}
-                      uoms={uoms}
+                      uoms={pickerOptions(allowedUoms.get(input.itemId), uoms)}
                       readOnly={readOnly}
                       onQtyChange={(qtyPerBatch) => updateInput(input.localId, { qtyPerBatch })}
                       onUomChange={(uomId) => updateInput(input.localId, { uomId })}
@@ -348,7 +355,7 @@ export function StageEditorPanel({
                   <QtyRow
                     qty={output.qtyPerBatch}
                     uomId={output.uomId}
-                    uoms={uoms}
+                    uoms={pickerOptions(allowedUoms.get(output.itemId), uoms)}
                     readOnly={readOnly}
                     onQtyChange={(qtyPerBatch) => updateOutput(output.key, { qtyPerBatch })}
                     onUomChange={(uomId) => updateOutput(output.key, { uomId })}

Frontend/erp-system/app/dashboard/production/templates/[id]/page.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import { useCallback, useEffect, useMemo, useState } from "react"
+import { Suspense, useCallback, useEffect, useMemo, useState } from "react"
 import { useParams, useRouter, useSearchParams } from "next/navigation"
 import Link from "next/link"
 import {
@@ -142,7 +142,7 @@ function stagesNamedIn(detail: string | undefined, stageNodes: Node[]): Set<stri
   return new Set(named.map((n) => n.id))
 }
 
-export default function TemplateBuilderPage() {
+function TemplateBuilderContent() {
   const params = useParams<{ id: string }>()
   const searchParams = useSearchParams()
   const router = useRouter()
@@ -806,3 +806,11 @@ export default function TemplateBuilderPage() {
     </div>
   )
 }
+
+export default function TemplateBuilderPage() {
+  return (
+    <Suspense fallback={<Skeleton className="h-[60vh] w-full rounded-2xl" />}>
+      <TemplateBuilderContent />
+    </Suspense>
+  )
+}

Frontend/erp-system/app/dashboard/products/[id]/UomConversionsPanel.tsx

@@ -0,0 +1,193 @@
+"use client"
+
+// Per-item UOM conversion editor (FR-MD-02).
+//
+// Until this panel existed, `PUT /items/{id}/uom-conversions` had no caller anywhere in the
+// app: conversions were typed, and had an API client method, but no screen could create one.
+// That made every non-base UOM unusable — a user could pick "Box-12" on an invoice line and
+// only discover at post time that the item had no conversion for it.
+//
+// Direction is fixed and not user-editable: a row always converts **into** the item's base
+// UOM. The server enforces that (`toUom` must equal `baseUomId`), because the conversion
+// engine only ever looks up `<other> → base` and never inverts a factor. Rendering `toUom`
+// as fixed text rather than a second picker is what keeps the two in step.
+import { useState } from "react"
+import { Plus, Save, Trash2 } from "lucide-react"
+
+import { itemsApi } from "@/lib/api/items"
+import { errorMessage } from "@/lib/error-map"
+import { validateConversionLine } from "@/lib/validations/master-data"
+import { UomConversion } from "@/types/master-data"
+
+import { Button } from "@/components/ui/button"
+import { Input } from "@/components/ui/input"
+import { Label } from "@/components/ui/label"
+import { FieldError } from "@/components/ui/field"
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
+import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
+import { toast } from "@/components/ui/toast"
+
+interface DraftRow {
+  key: string
+  fromUom: number | null
+  factor: string
+}
+
+interface Props {
+  itemId: number
+  baseUomId: number
+  conversions: UomConversion[]
+  uoms: { uomId: number; name: string }[]
+  /** Lets the parent refresh the item so `conversions` stays in sync after a save. */
+  onSaved: () => void
+}
+
+let rowSeq = 0
+const nextKey = () => `conv-${rowSeq++}`
+
+export function UomConversionsPanel({ itemId, baseUomId, conversions, uoms, onSaved }: Props) {
+  const [rows, setRows] = useState<DraftRow[]>(() =>
+    conversions.map((c) => ({ key: nextKey(), fromUom: c.fromUom, factor: String(c.factor) })),
+  )
+  const [errors, setErrors] = useState<Record<string, Record<string, string>>>({})
+  const [saving, setSaving] = useState(false)
+
+  const baseName = uoms.find((u) => u.uomId === baseUomId)?.name ?? "base UOM"
+  // The base UOM converts to itself implicitly; offering it here would only produce a 422.
+  const selectableUoms = uoms.filter((u) => u.uomId !== baseUomId)
+
+  function updateRow(key: string, patch: Partial<DraftRow>) {
+    setRows((prev) => prev.map((r) => (r.key === key ? { ...r, ...patch } : r)))
+  }
+
+  function addRow() {
+    setRows((prev) => [...prev, { key: nextKey(), fromUom: null, factor: "" }])
+  }
+
+  function removeRow(key: string) {
+    setRows((prev) => prev.filter((r) => r.key !== key))
+  }
+
+  async function handleSave() {
+    const nextErrors: Record<string, Record<string, string>> = {}
+    for (const row of rows) {
+      const rowErrors = validateConversionLine({ fromUom: row.fromUom, toUom: baseUomId, factor: row.factor })
+      if (Object.keys(rowErrors).length > 0) nextErrors[row.key] = rowErrors
+    }
+
+    // The unique index is on (item, from, to); catching it here beats a 400 from the server.
+    const chosen = rows.map((r) => r.fromUom).filter((u): u is number => u !== null)
+    const duplicates = chosen.filter((u, i) => chosen.indexOf(u) !== i)
+    for (const row of rows) {
+      if (row.fromUom !== null && duplicates.includes(row.fromUom)) {
+        nextErrors[row.key] = { ...nextErrors[row.key], fromUom: "One conversion per unit" }
+      }
+    }
+
+    setErrors(nextErrors)
+    if (Object.keys(nextErrors).length > 0) return
+
+    setSaving(true)
+    try {
+      // A full replace, matching the server's upsert semantics: an empty list clears them all,
+      // which is also how a user detaches conversions before changing the base UOM.
+      await itemsApi.updateUomConversions(itemId, {
+        conversions: rows.map((r) => ({ fromUom: r.fromUom as number, toUom: baseUomId, factor: Number(r.factor) })),
+      })
+      toast.success("Conversions saved", `${rows.length} conversion(s) against ${baseName}`)
+      onSaved()
+    } catch (err) {
+      toast.error("Could not save conversions", errorMessage(err))
+    } finally {
+      setSaving(false)
+    }
+  }
+
+  return (
+    <div className="flex flex-col gap-4 rounded-lg border border-border bg-card p-5">
+      <div className="flex flex-col gap-1">
+        <Label className="text-base font-semibold">UOM conversions</Label>
+        <p className="text-sm text-muted-foreground">
+          Units this item can be bought, sold, or produced in besides {baseName}. Each row says how many{" "}
+          {baseName} one of that unit is worth — a Box of 12 pieces is a factor of 12. Stock is always stored in{" "}
+          {baseName}.
+        </p>
+      </div>
+
+      {rows.length === 0 ? (
+        <p className="text-sm text-muted-foreground">
+          No conversions — this item can only be transacted in {baseName}.
+        </p>
+      ) : (
+        <Table>
+          <TableHeader>
+            <TableRow>
+              <TableHead className="w-64">Unit</TableHead>
+              <TableHead className="w-40 text-right">Factor</TableHead>
+              <TableHead>Converts to</TableHead>
+              <TableHead className="w-16" />
+            </TableRow>
+          </TableHeader>
+          <TableBody>
+            {rows.map((row) => (
+              <TableRow key={row.key}>
+                <TableCell>
+                  <Select<number | null>
+                    value={row.fromUom}
+                    onValueChange={(v) => updateRow(row.key, { fromUom: v })}
+                    items={selectableUoms.map((u) => ({ label: u.name, value: u.uomId }))}
+                  >
+                    <SelectTrigger className="h-11! w-full text-base" aria-invalid={!!errors[row.key]?.fromUom}>
+                      <SelectValue placeholder="Select unit" />
+                    </SelectTrigger>
+                    <SelectContent>
+                      {selectableUoms.map((u) => (
+                        <SelectItem key={u.uomId} value={u.uomId} className="text-base">
+                          {u.name}
+                        </SelectItem>
+                      ))}
+                    </SelectContent>
+                  </Select>
+                  <FieldError errors={[errors[row.key]?.fromUom ? { message: errors[row.key].fromUom } : undefined]} />
+                </TableCell>
+                <TableCell className="text-right">
+                  <Input
+                    type="number"
+                    min="0"
+                    step="0.000001"
+                    value={row.factor}
+                    onChange={(e) => updateRow(row.key, { factor: e.target.value })}
+                    aria-invalid={!!errors[row.key]?.factor}
+                    className="text-right"
+                  />
+                  <FieldError errors={[errors[row.key]?.factor ? { message: errors[row.key].factor } : undefined]} />
+                </TableCell>
+                <TableCell className="text-base text-muted-foreground">
+                  {row.factor && Number(row.factor) > 0
+                    ? `1 ${uoms.find((u) => u.uomId === row.fromUom)?.name ?? "unit"} = ${Number(row.factor)} ${baseName}`
+                    : baseName}
+                </TableCell>
+                <TableCell>
+                  <Button variant="ghost" size="icon" onClick={() => removeRow(row.key)} aria-label="Remove conversion">
+                    <Trash2 className="size-5 text-destructive" />
+                  </Button>
+                </TableCell>
+              </TableRow>
+            ))}
+          </TableBody>
+        </Table>
+      )}
+
+      <div className="flex justify-between gap-3">
+        <Button variant="outline" onClick={addRow}>
+          <Plus className="size-5" />
+          Add conversion
+        </Button>
+        <Button onClick={handleSave} disabled={saving}>
+          <Save className="size-5" />
+          {saving ? "Saving…" : "Save conversions"}
+        </Button>
+      </div>
+    </div>
+  )
+}

Frontend/erp-system/app/dashboard/products/[id]/page.tsx

@@ -11,9 +11,12 @@ import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage, fieldErrors } from "@/lib/error-map"
 import { validateItemForm } from "@/lib/validations/master-data"
+import { uomName } from "@/lib/uom"
 import { cn } from "@/lib/utils"
 import { Item, StockNature, TrackingMode } from "@/types/master-data"
 
+import { UomConversionsPanel } from "./UomConversionsPanel"
+
 import { Badge } from "@/components/ui/badge"
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Input } from "@/components/ui/input"
@@ -92,7 +95,9 @@ export default function ItemDetailPage() {
   useEffect(() => {
     if (!Number.isFinite(itemId)) return
     load()
-    Promise.all([categoriesApi.list(), uomsApi.list(), warehousesApi.list({ pageSize: 200 })])
+    // pageSize matters here: the default page would silently truncate the UOM list as the
+    // master grows, hiding units from the base-UOM picker and the conversions editor.
+    Promise.all([categoriesApi.list(), uomsApi.list({ pageSize: 200 }), warehousesApi.list({ pageSize: 200 })])
       .then(([cat, uo, wh]) => {
         setCategories(cat.items)
         setUoms(uo.items)
@@ -155,9 +160,6 @@ export default function ItemDetailPage() {
     }
   }
 
-  function uomName(uomId: number) {
-    return uoms.find((u) => u.uomId === uomId)?.name ?? `#${uomId}`
-  }
 
   if (loadError && !item) {
     return (
@@ -188,7 +190,7 @@ export default function ItemDetailPage() {
               <h1 className="text-2xl font-bold text-foreground">{item.sku}</h1>
               <Badge
                 variant="outline"
-                className={cn("h-6 w-fit justify-center border-transparent px-2.5 text-sm", item.status === "Active" ? "bg-success/10 text-success" : "bg-muted text-muted-foreground")}
+                className={cn("h-6 w-fit justify-center border-transparent px-2.5 text-sm", item.status === "Active" ? "bg-success/10 text-success" : "bg-destructive/10 text-destructive")}
               >
                 {item.status}
               </Badge>
@@ -321,8 +323,19 @@ export default function ItemDetailPage() {
       </div>
 
       <p className="text-sm text-muted-foreground">
-        {uomName(item.baseUomId)} is the base UOM — every transaction converts to and stores quantities in base UOM (FR-MD-03).
+        {uomName(item.baseUomId, uoms)} is the base UOM — every transaction converts to and stores quantities in base UOM (FR-MD-03).
       </p>
+
+      <UomConversionsPanel
+        // Remount when the saved set changes so the editor's draft rows re-seed from the
+        // server's response rather than keeping stale local state after a save or reload.
+        key={item.conversions.map((c) => `${c.conversionId}:${c.factor}`).join("|")}
+        itemId={item.itemId}
+        baseUomId={item.baseUomId}
+        conversions={item.conversions}
+        uoms={uoms}
+        onSaved={load}
+      />
     </div>
   )
 }

Frontend/erp-system/app/dashboard/products/brands/page.tsx

@@ -257,7 +257,15 @@ export default function BrandsPage() {
                   <TableCell className="px-3 py-3.5 text-muted-foreground">#{b.brandId}</TableCell>
                   <TableCell className="px-3 py-3.5 font-medium">{b.name}</TableCell>
                   <TableCell className="px-3 py-3.5">
-                    <Badge variant={b.status === "Active" ? "default" : "secondary"}>{b.status}</Badge>
+                    <Badge
+                      variant="outline"
+                      className={cn(
+                        "border-transparent",
+                        b.status === "Active" ? "bg-success/10 text-success" : "bg-destructive/10 text-destructive"
+                      )}
+                    >
+                      {b.status}
+                    </Badge>
                   </TableCell>
                   <TableCell className="px-3 py-3.5 text-muted-foreground">{new Date(b.createdAt).toLocaleDateString()}</TableCell>
                   <TableCell className="px-3 py-3.5">

Frontend/erp-system/app/dashboard/products/categories/[id]/page.tsx

@@ -7,6 +7,7 @@ import { Ban, CheckCircle2, Network, Pencil, Plus } from "lucide-react"
 import { categoriesApi, subCategoriesApi } from "@/lib/api/categories"
 import { errorMessage } from "@/lib/error-map"
 import { validateCategoryName } from "@/lib/validations/master-data"
+import { cn } from "@/lib/utils"
 import { Category, SubCategory } from "@/types/master-data"
 
 import { AlertDialog, AlertDialogContent, AlertDialogTrigger } from "@/components/ui/alert-dialog"
@@ -181,7 +182,15 @@ export default function CategorySubCategoriesPage() {
                 <TableCell className="px-3 py-3.5 text-muted-foreground">#{s.subCategoryId}</TableCell>
                 <TableCell className="px-3 py-3.5 font-medium">{s.name}</TableCell>
                 <TableCell className="px-3 py-3.5">
-                  <Badge variant={s.status === "Active" ? "default" : "secondary"}>{s.status}</Badge>
+                  <Badge
+                    variant="outline"
+                    className={cn(
+                      "border-transparent",
+                      s.status === "Active" ? "bg-success/10 text-success" : "bg-destructive/10 text-destructive"
+                    )}
+                  >
+                    {s.status}
+                  </Badge>
                 </TableCell>
                 <TableCell className="px-3 py-3.5 text-muted-foreground">{new Date(s.createdAt).toLocaleDateString()}</TableCell>
                 <TableCell className="px-3 py-3.5">

Frontend/erp-system/app/dashboard/products/categories/page.tsx

@@ -256,7 +256,15 @@ export default function CategoriesPage() {
                   <TableCell className="px-3 py-3.5 text-muted-foreground">#{c.categoryId}</TableCell>
                   <TableCell className="px-3 py-3.5 font-medium">{c.name}</TableCell>
                   <TableCell className="px-3 py-3.5">
-                    <Badge variant={c.status === "Active" ? "default" : "secondary"}>{c.status}</Badge>
+                    <Badge
+                      variant="outline"
+                      className={cn(
+                        "border-transparent",
+                        c.status === "Active" ? "bg-success/10 text-success" : "bg-destructive/10 text-destructive"
+                      )}
+                    >
+                      {c.status}
+                    </Badge>
                   </TableCell>
                   <TableCell className="px-3 py-3.5 text-muted-foreground">{new Date(c.createdAt).toLocaleDateString()}</TableCell>
                   <TableCell className="px-3 py-3.5">

Frontend/erp-system/app/dashboard/products/page.tsx

@@ -240,7 +240,7 @@ export default function ItemsPage() {
                       variant="outline"
                       className={cn(
                         "h-6 w-fit justify-center border-transparent px-2.5 text-sm",
-                        item.status === "Active" ? "bg-success/10 text-success" : "bg-muted text-muted-foreground"
+                        item.status === "Active" ? "bg-success/10 text-success" : "bg-destructive/10 text-destructive"
                       )}
                     >
                       {item.status}

Frontend/erp-system/app/dashboard/receiving/grn/[id]/page.tsx

@@ -8,6 +8,7 @@ import { CheckCircle2, PackageCheck, PackageX, ShieldAlert, XCircle } from "luci
 import { grnsApi } from "@/lib/api/grns"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { itemsApi } from "@/lib/api/items"
+import { uomName } from "@/lib/uom"
 import { uomsApi } from "@/lib/api/uoms"
 import { errorMessage } from "@/lib/error-map"
 import { cn } from "@/lib/utils"
@@ -57,7 +58,7 @@ export default function GrnDetailPage() {
     return items.find((i) => i.itemId === itemId)
   }
   function uomFor(uomId: number) {
-    return uoms.find((u) => u.uomId === uomId)?.name ?? `#${uomId}`
+    return uomName(uomId, uoms)
   }
   function binFor(binId: number | null) {
     if (!binId) return "—"

Frontend/erp-system/app/dashboard/receiving/grn/new/page.tsx

@@ -13,6 +13,8 @@ import { itemsApi } from "@/lib/api/items"
 import { uomsApi } from "@/lib/api/uoms"
 import { errorMessage } from "@/lib/error-map"
 import { validateLine, splitSerials, grnHeaderSchema } from "@/lib/validations/grn"
+import { basePreview, pickerOptions, uomName } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { cn } from "@/lib/utils"
 import { CreateGrnLineInput, HoldStatus } from "@/types/grn"
 import { PurchaseOrder, PurchaseOrderSummary } from "@/types/procurement"
@@ -108,12 +110,14 @@ export default function NewGrnPage() {
   const [submitError, setSubmitError] = useState<string | null>(null)
   const [submitting, setSubmitting] = useState(false)
   const [refreshingItems, setRefreshingItems] = useState(false)
+  const allowedUoms = useAllowedUoms()
 
   useEffect(() => {
     Promise.all([
       warehousesApi.list(),
       itemsApi.list({ pageSize: 200, status: "Active" }),
-      uomsApi.list(),
+      // pageSize: without it the default page silently truncates the unit list.
+      uomsApi.list({ pageSize: 200 }),
       vendorsApi.list({ pageSize: 200, status: "Active" }),
       purchaseOrdersApi.list({ pageSize: 200 }),
     ])
@@ -155,13 +159,18 @@ export default function NewGrnPage() {
     setHeaderError(null)
     try {
       const po: PurchaseOrder = await purchaseOrdersApi.get(nextPoId)
-      const openLines = po.lines.filter((l) => l.qtyReceived < l.qty)
+      // Open-ness is decided on the base pair, matching the server's close condition —
+      // qty/qtyReceived are PO-UOM display figures derived by division and can drift.
+      const openLines = po.lines.filter((l) => l.qtyReceivedBase < l.qtyBase)
       if (openLines.length === 0) {
         setHeaderError("This purchase order has no open (unreceived) lines.")
         setLines([])
         return
       }
       setWarehouseId((prev) => prev ?? openLines[0].warehouseId)
+      // The receiving lines keep the PO's UOM, so preload each item's allowed units for the
+      // few lines a user may switch to a different pack size.
+      openLines.forEach((l) => allowedUoms.load(l.itemId))
       setLines(
         openLines.map(
           (l): DraftLine => ({
@@ -440,220 +449,235 @@ export default function NewGrnPage() {
 
             {!poLoading && lines.length > 0 && (
               <div className="overflow-x-auto">
-              <Table className="text-base">
-                <TableHeader>
-                  <TableRow>
-                    <TableHead className="h-12 w-96 px-3 text-sm">Item</TableHead>
-                    <TableHead className="h-12 w-24 px-3 text-sm">UOM</TableHead>
-                    <TableHead className="h-12 w-28 px-3 text-sm">Bin</TableHead>
-                    <TableHead className="h-12 w-20 px-3 text-sm">Qty</TableHead>
-                    <TableHead className="h-12 w-28 px-3 text-sm">Unit cost</TableHead>
-                    <TableHead className="h-12 w-24 px-3 text-sm">Disc %</TableHead>
-                    <TableHead className="h-12 w-24 px-3 text-sm">VAT %</TableHead>
-                    <TableHead className="h-12 w-28 px-3 text-sm text-right">Line total</TableHead>
-                    <TableHead className="h-12 w-56 px-3 text-sm">Hold status</TableHead>
-                    <TableHead className="h-12 w-44 px-3 text-sm">Batch / Serial</TableHead>
-                    <TableHead className="h-12 w-10 px-3" />
-                  </TableRow>
-                </TableHeader>
-                <TableBody>
-                  {lines.map((line) => {
-                    const item = itemFor(line.itemId)
-                    const errors = lineErrors[line.key] ?? {}
-                    return (
-                      <TableRow key={line.key}>
-                        <TableCell className="px-3 py-3 align-top">
-                          {line.poLineId ? (
-                            <div className="flex h-11 items-center text-base">
-                              {item ? `${item.sku} — ${item.name}` : `Item #${line.itemId}`}
-                            </div>
-                          ) : (
-                            <>
-                              <Select<number | null> value={line.itemId} onValueChange={(v) => updateLine(line.key, { itemId: v })}>
-                                <SelectTrigger className="h-11! w-full text-base" aria-invalid={!!errors.itemId}>
-                                  <SelectValue placeholder="Select item" />
-                                </SelectTrigger>
-                                <SelectContent>
-                                  {(items ?? []).map((i) => (
-                                    <SelectItem key={i.itemId} value={i.itemId} className="text-base">
-                                      {i.sku} — {i.name}
-                                    </SelectItem>
-                                  ))}
-                                </SelectContent>
-                              </Select>
-                              <FieldError errors={[errors.itemId ? { message: errors.itemId } : undefined]} />
-                            </>
-                          )}
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          {line.poLineId ? (
-                            <div className="flex h-11 items-center text-base">
-                              {uoms?.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}
-                            </div>
-                          ) : (
-                            <>
-                              <Select<number | null> value={line.uomId} onValueChange={(v) => updateLine(line.key, { uomId: v })}>
-                                <SelectTrigger className="h-11! w-full text-base" aria-invalid={!!errors.uomId}>
-                                  <SelectValue placeholder="UOM" />
-                                </SelectTrigger>
-                                <SelectContent>
-                                  {(uoms ?? []).map((u) => (
-                                    <SelectItem key={u.uomId} value={u.uomId} className="text-base">
-                                      {u.name}
-                                    </SelectItem>
-                                  ))}
-                                </SelectContent>
-                              </Select>
-                              <FieldError errors={[errors.uomId ? { message: errors.uomId } : undefined]} />
-                            </>
-                          )}
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          <Select<number | null> value={line.binId} onValueChange={(v) => updateLine(line.key, { binId: v })}>
-                            <SelectTrigger className="h-11! w-full text-base">
-                              <SelectValue placeholder="None" />
-                            </SelectTrigger>
-                            <SelectContent>
-                              {bins.map((b) => (
-                                <SelectItem key={b.binId} value={b.binId} className="text-base">
-                                  {b.code}
-                                </SelectItem>
-                              ))}
-                            </SelectContent>
-                          </Select>
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          <Input
-                            type="number"
-                            min="0"
-                            step="any"
-                            value={line.qty}
-                            aria-invalid={!!errors.qty}
-                            onChange={(e) => updateLine(line.key, { qty: e.target.value })}
-                            className="h-11 text-base"
-                          />
-                          <FieldError errors={[errors.qty ? { message: errors.qty } : undefined]} />
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          <Input
-                            type="number"
-                            min="0"
-                            step="any"
-                            value={line.unitCost}
-                            aria-invalid={!!errors.unitCost}
-                            onChange={(e) => updateLine(line.key, { unitCost: e.target.value })}
-                            className="h-11 text-base"
-                          />
-                          <FieldError errors={[errors.unitCost ? { message: errors.unitCost } : undefined]} />
-                          {line.poUnitPrice !== null && Number(line.unitCost) !== line.poUnitPrice && (
-                            <p className="mt-1 text-xs text-warning">
-                              PO price {line.poUnitPrice.toFixed(2)} — variance recorded
-                            </p>
-                          )}
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          <Input
-                            type="number"
-                            min="0"
-                            max="100"
-                            step="any"
-                            value={line.discountPct}
-                            aria-invalid={!!errors.discountPct}
-                            onChange={(e) => updateLine(line.key, { discountPct: e.target.value })}
-                            className="h-11 text-base"
-                          />
-                          <FieldError errors={[errors.discountPct ? { message: errors.discountPct } : undefined]} />
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          <Input
-                            type="number"
-                            min="0"
-                            max="100"
-                            step="any"
-                            value={line.vatPct}
-                            aria-invalid={!!errors.vatPct}
-                            onChange={(e) => updateLine(line.key, { vatPct: e.target.value })}
-                            className="h-11 text-base"
-                          />
-                          <FieldError errors={[errors.vatPct ? { message: errors.vatPct } : undefined]} />
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top text-right tabular-nums">
-                          {(() => {
-                            const c = computeLine(line)
-                            return (
-                              <div className="flex h-11 flex-col justify-center">
-                                <span>{c.lineTotal.toFixed(2)}</span>
-                                <span className="text-xs text-muted-foreground">
-                                  net {c.receivedValue.toFixed(2)} + VAT {c.vatAmount.toFixed(2)}
-                                </span>
+                <Table className="text-base">
+                  <TableHeader>
+                    <TableRow>
+                      <TableHead className="h-12 w-56 px-3 text-sm">Item</TableHead>
+                      <TableHead className="h-12 w-24 px-3 text-sm">UOM</TableHead>
+                      <TableHead className="h-12 w-28 px-3 text-sm">Bin</TableHead>
+                      <TableHead className="h-12 w-32 px-3 text-sm">Qty</TableHead>
+                      <TableHead className="h-12 w-28 px-3 text-sm">Unit cost</TableHead>
+                      <TableHead className="h-12 w-24 px-3 text-sm">Disc %</TableHead>
+                      <TableHead className="h-12 w-24 px-3 text-sm">VAT %</TableHead>
+                      <TableHead className="h-12 w-28 px-3 text-sm text-right">Line total</TableHead>
+                      <TableHead className="h-12 w-56 px-3 text-sm">Hold status</TableHead>
+                      <TableHead className="h-12 w-44 px-3 text-sm">Batch / Serial</TableHead>
+                      <TableHead className="h-12 w-10 px-3" />
+                    </TableRow>
+                  </TableHeader>
+                  <TableBody>
+                    {lines.map((line) => {
+                      const item = itemFor(line.itemId)
+                      const errors = lineErrors[line.key] ?? {}
+                      return (
+                        <TableRow key={line.key}>
+                          <TableCell className="px-3 py-3 align-top">
+                            {line.poLineId ? (
+                              <div className="flex h-11 items-center text-base">
+                                {item ? `${item.sku} — ${item.name}` : `Item #${line.itemId}`}
                               </div>
-                            )
-                          })()}
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          <Select<HoldStatus>
-                            value={line.holdStatus}
-                            onValueChange={(v) => v && updateLine(line.key, { holdStatus: v })}
-                          >
-                            <SelectTrigger className="h-11! w-full text-base">
-                              <SelectValue />
-                            </SelectTrigger>
-                            <SelectContent>
-                              <SelectItem value="Available" className="text-base">Available</SelectItem>
-                              <SelectItem value="OnHold" className="text-base">On hold (inspection)</SelectItem>
-                            </SelectContent>
-                          </Select>
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          {item?.trackingMode === "Batch" && (
-                            <div className="flex flex-col gap-1.5">
-                              <Input
-                                placeholder="Batch no."
-                                value={line.batchNo}
-                                aria-invalid={!!errors.batchNo}
-                                onChange={(e) => updateLine(line.key, { batchNo: e.target.value })}
-                                className="h-9 text-sm"
-                              />
-                              <Input
-                                type="date"
-                                value={line.expiryDate}
-                                onChange={(e) => updateLine(line.key, { expiryDate: e.target.value })}
-                                className="h-9 text-sm"
-                              />
-                              <FieldError errors={[errors.batchNo ? { message: errors.batchNo } : undefined]} />
-                            </div>
-                          )}
-                          {item?.trackingMode === "Serial" && (
-                            <div className="flex flex-col gap-1.5">
-                              <textarea
-                                placeholder="One serial per line"
-                                value={line.serialNumbersText}
-                                aria-invalid={!!errors.serialNumbers}
-                                onChange={(e) => updateLine(line.key, { serialNumbersText: e.target.value })}
-                                className="min-h-16 w-full rounded-lg border border-input bg-transparent p-2 text-sm outline-none focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/50"
-                              />
-                              <FieldError errors={[errors.serialNumbers ? { message: errors.serialNumbers } : undefined]} />
-                            </div>
-                          )}
-                          {(!item || item.trackingMode === "None") && (
-                            <span className="text-sm text-muted-foreground">—</span>
-                          )}
-                        </TableCell>
-                        <TableCell className="px-3 py-3 align-top">
-                          <Button type="button" variant="ghost" size="icon" onClick={() => removeLine(line.key)} aria-label="Remove line">
-                            <Trash2 className="size-5" />
-                          </Button>
-                        </TableCell>
-                      </TableRow>
-                    )
-                  })}
-                </TableBody>
-              </Table>
+                            ) : (
+                              <>
+                                <Select<number | null>
+                                  value={line.itemId}
+                                  onValueChange={(v) => {
+                                    // Reset the unit to the item's base and load its allowed
+                                    // units — a UOM carried over from the previous item would
+                                    // usually have no conversion for the new one.
+                                    allowedUoms.load(v)
+                                    updateLine(line.key, { itemId: v, uomId: itemFor(v)?.baseUomId ?? null })
+                                  }}
+                                >
+                                  <SelectTrigger className="h-11! w-full text-base" aria-invalid={!!errors.itemId}>
+                                    <SelectValue placeholder="Select item" />
+                                  </SelectTrigger>
+                                  <SelectContent>
+                                    {(items ?? []).map((i) => (
+                                      <SelectItem key={i.itemId} value={i.itemId} className="text-base">
+                                        {i.sku} — {i.name}
+                                      </SelectItem>
+                                    ))}
+                                  </SelectContent>
+                                </Select>
+                                <FieldError errors={[errors.itemId ? { message: errors.itemId } : undefined]} />
+                              </>
+                            )}
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            {line.poLineId ? (
+                              <div className="flex h-11 items-center text-base">
+                                {uomName(line.uomId, uoms ?? [])}
+                              </div>
+                            ) : (
+                              <>
+                                <Select<number | null> value={line.uomId} onValueChange={(v) => updateLine(line.key, { uomId: v })}>
+                                  <SelectTrigger className="h-11! w-full text-base" aria-invalid={!!errors.uomId}>
+                                    <SelectValue placeholder="UOM" />
+                                  </SelectTrigger>
+                                  <SelectContent>
+                                    {pickerOptions(allowedUoms.get(line.itemId), uoms ?? []).map((u) => (
+                                      <SelectItem key={u.uomId} value={u.uomId} className="text-base">
+                                        {u.name}
+                                      </SelectItem>
+                                    ))}
+                                  </SelectContent>
+                                </Select>
+                                <FieldError errors={[errors.uomId ? { message: errors.uomId } : undefined]} />
+                              </>
+                            )}
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Select<number | null> value={line.binId} onValueChange={(v) => updateLine(line.key, { binId: v })}>
+                              <SelectTrigger className="h-11! w-full text-base">
+                                <SelectValue placeholder="None" />
+                              </SelectTrigger>
+                              <SelectContent>
+                                {bins.map((b) => (
+                                  <SelectItem key={b.binId} value={b.binId} className="text-base">
+                                    {b.code}
+                                  </SelectItem>
+                                ))}
+                              </SelectContent>
+                            </Select>
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Input
+                              type="number"
+                              min="0"
+                              step="any"
+                              value={line.qty}
+                              aria-invalid={!!errors.qty}
+                              onChange={(e) => updateLine(line.key, { qty: e.target.value })}
+                              className="h-11 text-base"
+                            />
+                            {/* Shows what will actually hit stock when receiving in a pack unit. */}
+                            {basePreview(Number(line.qty), line.uomId, allowedUoms.get(line.itemId) ?? []) && (
+                              <p className="mt-1 text-xs text-muted-foreground">
+                                {basePreview(Number(line.qty), line.uomId, allowedUoms.get(line.itemId) ?? [])}
+                              </p>
+                            )}
+                            <FieldError errors={[errors.qty ? { message: errors.qty } : undefined]} />
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Input
+                              type="number"
+                              min="0"
+                              step="any"
+                              value={line.unitCost}
+                              aria-invalid={!!errors.unitCost}
+                              onChange={(e) => updateLine(line.key, { unitCost: e.target.value })}
+                              className="h-11 text-base"
+                            />
+                            <FieldError errors={[errors.unitCost ? { message: errors.unitCost } : undefined]} />
+                            {line.poUnitPrice !== null && Number(line.unitCost) !== line.poUnitPrice && (
+                              <p className="mt-1 text-xs text-warning">
+                                PO price {line.poUnitPrice.toFixed(2)} — variance recorded
+                              </p>
+                            )}
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Input
+                              type="number"
+                              min="0"
+                              max="100"
+                              step="any"
+                              value={line.discountPct}
+                              aria-invalid={!!errors.discountPct}
+                              onChange={(e) => updateLine(line.key, { discountPct: e.target.value })}
+                              className="h-11 text-base"
+                            />
+                            <FieldError errors={[errors.discountPct ? { message: errors.discountPct } : undefined]} />
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Input
+                              type="number"
+                              min="0"
+                              max="100"
+                              step="any"
+                              value={line.vatPct}
+                              aria-invalid={!!errors.vatPct}
+                              onChange={(e) => updateLine(line.key, { vatPct: e.target.value })}
+                              className="h-11 text-base"
+                            />
+                            <FieldError errors={[errors.vatPct ? { message: errors.vatPct } : undefined]} />
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top text-right tabular-nums">
+                            {(() => {
+                              const c = computeLine(line)
+                              return (
+                                <div className="flex h-11 flex-col justify-center">
+                                  <span>{c.lineTotal.toFixed(2)}</span>
+                                  <span className="text-xs text-muted-foreground">
+                                    net {c.receivedValue.toFixed(2)} + VAT {c.vatAmount.toFixed(2)}
+                                  </span>
+                                </div>
+                              )
+                            })()}
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Select<HoldStatus>
+                              value={line.holdStatus}
+                              onValueChange={(v) => v && updateLine(line.key, { holdStatus: v })}
+                            >
+                              <SelectTrigger className="h-11! w-full text-base">
+                                <SelectValue />
+                              </SelectTrigger>
+                              <SelectContent>
+                                <SelectItem value="Available" className="text-base">Available</SelectItem>
+                                <SelectItem value="OnHold" className="text-base">On hold (inspection)</SelectItem>
+                              </SelectContent>
+                            </Select>
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            {item?.trackingMode === "Batch" && (
+                              <div className="flex flex-col gap-1.5">
+                                <Input
+                                  placeholder="Batch no."
+                                  value={line.batchNo}
+                                  aria-invalid={!!errors.batchNo}
+                                  onChange={(e) => updateLine(line.key, { batchNo: e.target.value })}
+                                  className="h-9 text-sm"
+                                />
+                                <Input
+                                  type="date"
+                                  value={line.expiryDate}
+                                  onChange={(e) => updateLine(line.key, { expiryDate: e.target.value })}
+                                  className="h-9 text-sm"
+                                />
+                                <FieldError errors={[errors.batchNo ? { message: errors.batchNo } : undefined]} />
+                              </div>
+                            )}
+                            {item?.trackingMode === "Serial" && (
+                              <div className="flex flex-col gap-1.5">
+                                <textarea
+                                  placeholder="One serial per line"
+                                  value={line.serialNumbersText}
+                                  aria-invalid={!!errors.serialNumbers}
+                                  onChange={(e) => updateLine(line.key, { serialNumbersText: e.target.value })}
+                                  className="min-h-16 w-full rounded-lg border border-input bg-transparent p-2 text-sm outline-none focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/50"
+                                />
+                                <FieldError errors={[errors.serialNumbers ? { message: errors.serialNumbers } : undefined]} />
+                              </div>
+                            )}
+                            {(!item || item.trackingMode === "None") && (
+                              <span className="text-sm text-muted-foreground">—</span>
+                            )}
+                          </TableCell>
+                          <TableCell className="px-3 py-3 align-top">
+                            <Button type="button" variant="ghost" size="icon" onClick={() => removeLine(line.key)} aria-label="Remove line">
+                              <Trash2 className="size-5" />
+                            </Button>
+                          </TableCell>
+                        </TableRow>
+                      )
+                    })}
+                  </TableBody>
+                </Table>
               </div>
             )}
 
             {!poLoading && lines.length > 0 && (
-              <div className="flex justify-end gap-6 pr-12 text-base">
+              <div className="flex justify-end gap-3 border-t border-border pt-4 text-base">
                 <span className="text-muted-foreground">Document total (incl. VAT)</span>
                 <span className="font-semibold tabular-nums">
                   {lines.reduce((sum, l) => sum + computeLine(l).lineTotal, 0).toFixed(2)}

Frontend/erp-system/app/dashboard/sales/bundles/[id]/page.tsx

@@ -3,12 +3,14 @@
 import { useEffect, useMemo, useState } from "react"
 import Link from "next/link"
 import { useParams, useRouter } from "next/navigation"
-import { ArrowLeft, CheckCircle2, Edit, Minus, Plus, Printer, Save, XCircle } from "lucide-react"
+import { ArrowLeft, CheckCircle2, Edit, ExternalLink, Minus, Plus, Printer, Save, XCircle } from "lucide-react"
 
 import { bundleApi } from "@/lib/api/bundles"
 import { itemsApi } from "@/lib/api/items"
 import { uomsApi } from "@/lib/api/uoms"
 import { errorMessage } from "@/lib/error-map"
+import { basePreview, pickerOptions } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
 import { Input } from "@/components/ui/input"
@@ -16,7 +18,7 @@ import { Label } from "@/components/ui/label"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { cn } from "@/lib/utils"
-import { BundleSale, BundleSaleTemplateSummary, BundleSaleTemplateLine, UpdateBundleSaleRequest } from "@/types/bundles"
+import { BundleSale, BundleSaleTemplate, BundleSaleTemplateSummary, BundleSaleTemplateLine, UpdateBundleSaleRequest } from "@/types/bundles"
 import { customersApi } from "@/lib/api/customers"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { usersApi } from "@/lib/api/users"
@@ -26,6 +28,18 @@ import { ManagedUser } from "@/types/users"
 
 type EditableLine = BundleSaleTemplateLine & { key: string }
 
+const createBlankLine = (templateLine?: BundleSaleTemplateLine): EditableLine => ({
+  key: crypto.randomUUID(),
+  bundleSaleTemplateLineId: templateLine?.bundleSaleTemplateLineId ?? 0,
+  itemId: templateLine?.itemId ?? 0,
+  uomId: templateLine?.uomId ?? 0,
+  warehouseId: templateLine?.warehouseId ?? 0,
+  qty: templateLine?.qty ?? 1,
+  unitPrice: templateLine?.unitPrice ?? 0,
+  includeInBundle: templateLine?.includeInBundle ?? true,
+  sortOrder: templateLine?.sortOrder ?? 0,
+})
+
 function statusClass(status: BundleSale["status"]) {
   switch (status) {
     case "Draft":
@@ -43,7 +57,9 @@ export default function BundleSaleDetailPage() {
   const bundleSaleId = Number(params.id)
   const [bundle, setBundle] = useState<BundleSale | null>(null)
   const [editing, setEditing] = useState(false)
+  const allowedUoms = useAllowedUoms()
   const [templates, setTemplates] = useState<BundleSaleTemplateSummary[]>([])
+  const [template, setTemplate] = useState<BundleSaleTemplate | null>(null)
   const [customers, setCustomers] = useState<Customer[]>([])
   const [items, setItems] = useState<ItemListItem[]>([])
   const [uoms, setUoms] = useState<Uom[]>([])
@@ -89,11 +105,15 @@ export default function BundleSaleDetailPage() {
         setTemplateId(data.bundleSaleTemplateId)
         setBundleName(data.bundleName)
         setBundlePrice(data.bundlePrice)
+        data.lines.forEach((line) => allowedUoms.load(line.itemId))
         setLines(
           data.lines.map((line) => ({
             key: `${line.bundleSaleLineId}`,
             bundleSaleTemplateLineId: line.bundleSaleLineId,
             itemId: line.itemId,
+            // Keep the UOM the line was saved with. This used to be forced back to the
+            // item's base because the server rewrote it that way; it now preserves what
+            // was entered, so overriding here would discard the user's choice.
             uomId: line.uomId,
             warehouseId: line.warehouseId,
             qty: line.qty,
@@ -104,7 +124,12 @@ export default function BundleSaleDetailPage() {
         )
       })
       .catch((err) => setError(errorMessage(err)))
-  }, [bundleSaleId, params.id])
+  }, [bundleSaleId, params.id, items])
+
+  useEffect(() => {
+    if (!templateId) return
+    bundleApi.getTemplate(templateId).then(setTemplate).catch((err) => setError(errorMessage(err)))
+  }, [templateId])
 
   const templateLabel = useMemo(() => templates.find((t) => t.bundleSaleTemplateId === templateId)?.templateName ?? "Template", [templates, templateId])
   const componentSubtotal = useMemo(() => lines.reduce((sum, line) => sum + Number(line.qty || 0) * Number(line.unitPrice || 0), 0), [lines])
@@ -116,9 +141,9 @@ export default function BundleSaleDetailPage() {
   }
 
   function addLine() {
-    const source = lines[lines.length - 1]
+    const source = template?.lines[0]
     if (!source) return
-    setLines((prev) => [...prev, { ...source, key: crypto.randomUUID() }])
+    setLines((prev) => [...prev, createBlankLine(source)])
   }
 
   function removeLine(key: string) {
@@ -170,6 +195,20 @@ export default function BundleSaleDetailPage() {
     }
   }
 
+  const shortageIssues = bundle && bundle.status === "Draft"
+    ? bundle.lines
+        .filter((line) => line.includeInBundle)
+        .filter((line) => Number(line.qty || 0) > 0)
+        .map((line) => ({
+          bundleSaleLineId: line.bundleSaleLineId,
+          itemId: line.itemId,
+          itemSku: items.find((item) => item.itemId === line.itemId)?.sku ?? `#${line.itemId}`,
+          itemName: items.find((item) => item.itemId === line.itemId)?.name ?? line.itemId.toString(),
+          warehouseId: line.warehouseId,
+          requestedQty: line.qty,
+        }))
+      : []
+
   async function cancelBundle() {
     if (!bundle) return
     setBusy(true)
@@ -236,6 +275,47 @@ export default function BundleSaleDetailPage() {
 
       {error ? <div className="rounded-lg border border-destructive/30 bg-destructive/5 p-5 text-base text-destructive">{error}</div> : null}
 
+      {bundle.status === "Draft" && shortageIssues.length > 0 ? (
+        <div className="rounded-lg border border-amber-200 bg-amber-50 p-4 text-sm text-amber-900">
+          <div className="flex flex-col gap-3 md:flex-row md:items-start md:justify-between">
+            <div>
+              <div className="font-semibold">Stock shortage detected before posting</div>
+              <div className="mt-1">This bundle cannot be posted until every included component has enough available stock in the selected warehouse.</div>
+            </div>
+            <Link
+              href="/dashboard/receiving/grn/new"
+              className="inline-flex h-9 items-center gap-2 self-start rounded-full border border-amber-300 bg-white px-4 text-sm font-medium text-amber-950 shadow-sm hover:bg-amber-100"
+            >
+              <ExternalLink className="size-4" />
+              Create GRN
+            </Link>
+          </div>
+          <div className="mt-3 overflow-x-auto">
+            <table className="w-full text-sm">
+              <thead className="text-left text-xs uppercase tracking-wide text-amber-900/70">
+                <tr>
+                  <th className="py-1 pr-3">Item</th>
+                  <th className="py-1 pr-3">Warehouse</th>
+                  <th className="py-1 pr-3 text-right">Requested</th>
+                </tr>
+              </thead>
+              <tbody>
+                {shortageIssues.map((issue) => (
+                  <tr key={issue.bundleSaleLineId} className="border-t border-amber-200/60">
+                    <td className="py-2 pr-3">
+                      <div className="font-medium">{issue.itemSku}</div>
+                      <div className="text-xs text-amber-900/70">{issue.itemName}</div>
+                    </td>
+                    <td className="py-2 pr-3">{issue.warehouseId}</td>
+                    <td className="py-2 pr-3 text-right font-mono tabular-nums">{issue.requestedQty.toFixed(0)}</td>
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        </div>
+      ) : null}
+
       <section className="rounded-2xl border bg-card p-4 shadow-sm">
         <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
           <div className="space-y-1.5">
@@ -304,7 +384,8 @@ export default function BundleSaleDetailPage() {
                       <Select value={line.itemId ? String(line.itemId) : "all"} onValueChange={(v) => {
                         const itemId = Number(v)
                         const item = items.find((candidate) => candidate.itemId === itemId)
-                        updateLine(line.key, { itemId, unitPrice: item?.salePrice ?? line.unitPrice })
+                        allowedUoms.load(itemId)
+                        updateLine(line.key, { itemId, uomId: item?.baseUomId ?? line.uomId, unitPrice: item?.salePrice ?? line.unitPrice })
                       }} disabled={!editing || !isDraft}>
                         <SelectTrigger className="h-9 text-sm">
                           <SelectValue placeholder="Select item" />
@@ -319,12 +400,14 @@ export default function BundleSaleDetailPage() {
                       </Select>
                     </TableCell>
                     <TableCell className="min-w-40">
-                      <Select value={line.uomId ? String(line.uomId) : "all"} onValueChange={(v) => updateLine(line.key, { uomId: v === "all" ? 0 : Number(v) })} disabled={!editing || !isDraft}>
+                      {/* Enabled now that bundle lines keep the entered UOM (the server
+                          snapshots QtyBase beside it instead of overwriting Qty). */}
+                      <Select value={line.uomId ? String(line.uomId) : "all"} onValueChange={(v) => updateLine(line.key, { uomId: v === "all" ? 0 : Number(v) })} disabled={!editing || !isDraft || !line.itemId}>
                         <SelectTrigger className="h-9 text-sm">
                           <SelectValue placeholder="Select UOM" />
                         </SelectTrigger>
                         <SelectContent>
-                          {uoms.map((uom) => (
+                          {pickerOptions(allowedUoms.get(line.itemId), uoms).map((uom) => (
                             <SelectItem key={uom.uomId} value={String(uom.uomId)}>
                               {uom.name}
                             </SelectItem>
@@ -332,12 +415,39 @@ export default function BundleSaleDetailPage() {
                         </SelectContent>
                       </Select>
                     </TableCell>
-                    <TableCell className="text-right w-28"><Input type="number" min="0" step="0.01" value={line.qty} onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })} disabled={!editing || !isDraft} className="text-right" /></TableCell>
+                    <TableCell className="text-right w-28">
+                      <Input type="number" min="0" step="0.01" value={line.qty} onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })} disabled={!editing || !isDraft} className="text-right" />
+                      {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? []) && (
+                        <p className="mt-1 text-xs text-muted-foreground">{basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? [])}</p>
+                      )}
+                    </TableCell>
                     <TableCell className="text-right w-32"><Input type="number" min="0" step="0.01" value={line.unitPrice} onChange={(e) => updateLine(line.key, { unitPrice: Number(e.target.value) })} disabled={!editing || !isDraft} className="text-right" /></TableCell>
-                    <TableCell className="text-right">{line.includeInBundle ? "Yes" : "No"}</TableCell>
+                    <TableCell className="text-right">
+                      {editing && isDraft ? (
+                        <button
+                          type="button"
+                          onClick={() => updateLine(line.key, { includeInBundle: !line.includeInBundle })}
+                          className={cn(
+                            "rounded-full px-3 py-1 text-xs font-medium",
+                            line.includeInBundle ? "bg-emerald-50 text-emerald-800" : "bg-muted text-muted-foreground"
+                          )}
+                        >
+                          {line.includeInBundle ? "Included" : "Excluded"}
+                        </button>
+                      ) : (
+                        line.includeInBundle ? "Included" : "Excluded"
+                      )}
+                    </TableCell>
                     {editing && isDraft ? <TableCell className="text-right"><Button type="button" variant="ghost" size="icon-sm" onClick={() => removeLine(line.key)} disabled={lines.length === 1}><Minus className="size-4" /></Button></TableCell> : null}
                   </TableRow>
                 ))}
+                {lines.length === 0 ? (
+                  <TableRow>
+                    <TableCell colSpan={editing && isDraft ? 6 : 5} className="py-10 text-center text-sm text-muted-foreground">
+                      No component rows yet. Click Add line to start.
+                    </TableCell>
+                  </TableRow>
+                ) : null}
             </TableBody>
           </Table>
         </div>

Frontend/erp-system/app/dashboard/sales/bundles/new/page.tsx

@@ -1,9 +1,9 @@
 "use client"
 
-import { useEffect, useMemo, useState } from "react"
+import { Suspense, useEffect, useMemo, useState } from "react"
 import { useRouter, useSearchParams } from "next/navigation"
 import Link from "next/link"
-import { ArrowLeft, Minus, Plus, Save } from "lucide-react"
+import { ArrowLeft, ExternalLink, Minus, Plus, Save } from "lucide-react"
 
 import { bundleApi } from "@/lib/api/bundles"
 import { customersApi } from "@/lib/api/customers"
@@ -12,10 +12,13 @@ import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { usersApi } from "@/lib/api/users"
 import { errorMessage } from "@/lib/error-map"
+import { basePreview, pickerOptions } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Input } from "@/components/ui/input"
 import { Label } from "@/components/ui/label"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
+import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { cn } from "@/lib/utils"
 import { toast } from "@/components/ui/toast"
@@ -26,9 +29,19 @@ import { BundleSaleTemplate, BundleSaleTemplateLine, BundleSaleTemplateSummary,
 
 type EditableLine = BundleSaleTemplateLine & { key: string }
 
-const blankLine = (source: BundleSaleTemplateLine): EditableLine => ({ ...source, key: crypto.randomUUID() })
+const createBlankLine = (templateLine?: BundleSaleTemplateLine): EditableLine => ({
+  key: crypto.randomUUID(),
+  bundleSaleTemplateLineId: templateLine?.bundleSaleTemplateLineId ?? 0,
+  itemId: templateLine?.itemId ?? 0,
+  uomId: templateLine?.uomId ?? 0,
+  warehouseId: templateLine?.warehouseId ?? 0,
+  qty: templateLine?.qty ?? 1,
+  unitPrice: templateLine?.unitPrice ?? 0,
+  includeInBundle: templateLine?.includeInBundle ?? true,
+  sortOrder: templateLine?.sortOrder ?? 0,
+})
 
-export default function NewBundleSalePage() {
+function NewBundleSaleContent() {
   const router = useRouter()
   const searchParams = useSearchParams()
   const templateFromQuery = searchParams.get("templateId")
@@ -50,6 +63,7 @@ export default function NewBundleSalePage() {
   const [loading, setLoading] = useState(true)
   const [saving, setSaving] = useState(false)
   const [submitError, setSubmitError] = useState<string | null>(null)
+  const allowedUoms = useAllowedUoms()
 
   useEffect(() => {
     Promise.all([
@@ -80,10 +94,21 @@ export default function NewBundleSalePage() {
     if (!templateId) return
     bundleApi.getTemplate(templateId).then((res) => {
       setTemplate(res)
-      setLines(res.lines.map(blankLine))
+      setLines(
+        res.lines.length > 0
+          ? res.lines.map((line) => {
+              // Load each component's allowed units so the picker narrows for template-seeded rows too.
+              allowedUoms.load(line.itemId)
+              // Keep the template's own UOM. Forcing it to the item's base while keeping the
+              // template's unitPrice would leave qty and price in different units, and
+              // componentSubtotal below multiplies the two.
+              return createBlankLine({ ...line, uomId: line.uomId })
+            })
+          : [createBlankLine()]
+      )
       setBundlePrice(res.lines.reduce((sum, line) => sum + line.qty * line.unitPrice, 0))
     }).catch((err) => setSubmitError(errorMessage(err)))
-  }, [templateId])
+  }, [items, templateId])
 
   const templateLabel = useMemo(() => template?.templateName ?? "Select template", [template])
   const componentSubtotal = useMemo(() => lines.reduce((sum, line) => sum + Number(line.qty || 0) * Number(line.unitPrice || 0), 0), [lines])
@@ -93,9 +118,7 @@ export default function NewBundleSalePage() {
   }
 
   function addLine() {
-    const source = lines[lines.length - 1] ?? template?.lines[0]
-    if (!source) return
-    setLines((prev) => [...prev, blankLine(source)])
+    setLines((prev) => [...prev, createBlankLine(template?.lines[0])])
   }
 
   function removeLine(key: string) {
@@ -150,6 +173,22 @@ export default function NewBundleSalePage() {
 
       {submitError ? <div className="rounded-lg border border-destructive/30 bg-destructive/5 p-5 text-base text-destructive">{submitError}</div> : null}
 
+      <div className="rounded-lg border border-amber-200 bg-amber-50 p-4 text-sm text-amber-900">
+        <div className="flex flex-col gap-3 md:flex-row md:items-start md:justify-between">
+          <div>
+            <div className="font-semibold">Need stock before saving this bundle?</div>
+            <div className="mt-1">Save the bundle as a draft first. After that, open the draft detail page to check shortages and create a GRN if needed.</div>
+          </div>
+          <Link
+            href="/dashboard/receiving/grn/new"
+            className="inline-flex h-9 items-center gap-2 self-start rounded-full border border-amber-300 bg-white px-4 text-sm font-medium text-amber-950 shadow-sm hover:bg-amber-100"
+          >
+            <ExternalLink className="size-4" />
+            Create GRN
+          </Link>
+        </div>
+      </div>
+
       <section className="rounded-2xl border bg-card p-4 shadow-sm">
         <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
           <div className="space-y-1.5">
@@ -221,13 +260,15 @@ export default function NewBundleSalePage() {
               {lines.map((line) => (
                 <TableRow key={line.key}>
                   <TableCell className="min-w-72">
-                      <Select value={line.itemId ? String(line.itemId) : "all"} onValueChange={(v) => {
+                    <Select value={line.itemId ? String(line.itemId) : "all"} onValueChange={(v) => {
                         const itemId = Number(v)
-                      const item = items.find((candidate) => candidate.itemId === itemId)
-                      updateLine(line.key, {
-                        itemId,
-                        unitPrice: item?.salePrice ?? line.unitPrice,
-                      })
+                        const item = items.find((candidate) => candidate.itemId === itemId)
+                        allowedUoms.load(itemId)
+                        updateLine(line.key, {
+                          itemId,
+                          uomId: item?.baseUomId ?? line.uomId,
+                          unitPrice: item?.salePrice ?? line.unitPrice,
+                        })
                     }}>
                       <SelectTrigger className="h-9 text-sm">
                         <SelectValue placeholder="Select item" />
@@ -242,12 +283,14 @@ export default function NewBundleSalePage() {
                     </Select>
                   </TableCell>
                   <TableCell className="min-w-40">
-                      <Select value={line.uomId ? String(line.uomId) : "all"} onValueChange={(v) => updateLine(line.key, { uomId: v === "all" ? 0 : Number(v) })}>
+                      {/* Enabled now that bundle lines keep the entered UOM: the server
+                          snapshots the base quantity beside it instead of overwriting qty. */}
+                      <Select value={line.uomId ? String(line.uomId) : "all"} onValueChange={(v) => updateLine(line.key, { uomId: v === "all" ? 0 : Number(v) })} disabled={!line.itemId}>
                       <SelectTrigger className="h-9 text-sm">
                         <SelectValue placeholder="Select UOM" />
                       </SelectTrigger>
                       <SelectContent>
-                        {uoms.map((uom) => (
+                        {pickerOptions(allowedUoms.get(line.itemId), uoms).map((uom) => (
                           <SelectItem key={uom.uomId} value={String(uom.uomId)}>
                             {uom.name}
                           </SelectItem>
@@ -255,14 +298,39 @@ export default function NewBundleSalePage() {
                       </SelectContent>
                     </Select>
                   </TableCell>
-                  <TableCell className="text-right w-28"><Input type="number" min="0" step="0.01" value={line.qty} onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })} className="text-right" /></TableCell>
+                  <TableCell className="text-right w-28">
+                    <Input type="number" min="0" step="0.01" value={line.qty} onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })} className="text-right" />
+                    {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? []) && (
+                      <p className="mt-1 text-xs text-muted-foreground">
+                        {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? [])}
+                      </p>
+                    )}
+                  </TableCell>
                   <TableCell className="text-right w-32"><Input type="number" min="0" step="0.01" value={line.unitPrice} onChange={(e) => updateLine(line.key, { unitPrice: Number(e.target.value) })} className="text-right" /></TableCell>
-                  <TableCell className="text-right">{line.includeInBundle ? "Yes" : "No"}</TableCell>
+                  <TableCell className="text-right">
+                    <button
+                      type="button"
+                      onClick={() => updateLine(line.key, { includeInBundle: !line.includeInBundle })}
+                      className={cn(
+                        "rounded-full px-3 py-1 text-xs font-medium",
+                        line.includeInBundle ? "bg-emerald-50 text-emerald-800" : "bg-muted text-muted-foreground"
+                      )}
+                    >
+                      {line.includeInBundle ? "Included" : "Excluded"}
+                    </button>
+                  </TableCell>
                   <TableCell className="text-right">
                     <Button type="button" variant="ghost" size="icon-sm" onClick={() => removeLine(line.key)} disabled={lines.length === 1}><Minus className="size-4" /></Button>
                   </TableCell>
                 </TableRow>
               ))}
+              {lines.length === 0 && (
+                <TableRow>
+                  <TableCell colSpan={6} className="py-10 text-center text-sm text-muted-foreground">
+                    No component rows yet. Click Add component to start.
+                  </TableCell>
+                </TableRow>
+              )}
             </TableBody>
           </Table>
         </div>
@@ -286,3 +354,11 @@ export default function NewBundleSalePage() {
     </div>
   )
 }
+
+export default function NewBundleSalePage() {
+  return (
+    <Suspense fallback={<Skeleton className="h-48 w-full" />}>
+      <NewBundleSaleContent />
+    </Suspense>
+  )
+}

Frontend/erp-system/app/dashboard/sales/bundles/page.tsx

@@ -84,7 +84,18 @@ export default function BundleSalesPage() {
       .catch((err) => setError(errorMessage(err)))
   }, [page, status, query, customerId, warehouseId])
 
-  const visibleRows = useMemo(() => rows ?? [], [rows])
+  const visibleRows = useMemo(
+    () =>
+      rows?.filter((row) => {
+        const matchesStatus = status === "All" || row.status === status
+        const matchesQuery =
+          `${row.bundleNo} ${row.bundleName} ${row.customerSnapshotName} ${row.bundleCode}`
+            .toLowerCase()
+            .includes(query.toLowerCase())
+        return matchesStatus && matchesQuery
+      }) ?? [],
+    [rows, query, status]
+  )
   const hasFilters = status !== "All" || query.length > 0 || customerId !== null || warehouseId !== null
   const bundleTotal = visibleRows.reduce((sum, row) => sum + row.grandTotal, 0)
   const printHref = `/print/sales/bundles?status=${encodeURIComponent(status)}&q=${encodeURIComponent(query)}&customerId=${customerId ?? ""}&warehouseId=${warehouseId ?? ""}`
@@ -125,7 +136,12 @@ export default function BundleSalesPage() {
             ))}
           </div>
           <div className="flex flex-1 flex-col gap-3 lg:flex-row lg:items-center lg:justify-end">
-            <Input value={searchInput} onChange={(e) => setSearchInput(e.target.value)} placeholder="Filter by bundle, code, or customer" className="h-12 w-full lg:max-w-sm" />
+            <Input
+              value={searchInput}
+              onChange={(e) => setSearchInput(e.target.value)}
+              placeholder="Filter by bundle, code, or customer"
+              className="h-12 w-full lg:max-w-sm"
+            />
             <Button variant="outline" size="sm" className="lg:ml-auto" onClick={() => setShowFilters((v) => !v)}>
               <Filter className="size-4" />
               Advanced

Frontend/erp-system/app/dashboard/sales/free-issues/new/page.tsx

@@ -10,6 +10,8 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { cn } from "@/lib/utils"
 import { errorMessage } from "@/lib/error-map"
+import { pickerOptions, uomName as resolveUomName } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
 import { itemsApi } from "@/lib/api/items"
@@ -70,6 +72,7 @@ export default function NewFreeIssuePage() {
   const [loading, setLoading] = useState(true)
   const [saving, setSaving] = useState(false)
   const [error, setError] = useState<string | null>(null)
+  const allowedUoms = useAllowedUoms()
 
   async function refreshRows() {
     const list = await salesApi.listFreeIssues({ pageSize: 50 })
@@ -88,7 +91,7 @@ export default function NewFreeIssuePage() {
           warehouseName: warehouse?.name ?? `Warehouse ${detail.data.warehouseId}`,
           itemName: item?.name ?? firstLine?.description ?? "—",
           itemSku: item?.sku ?? `SKU-${firstLine?.itemId ?? 0}`,
-          uomName: uom?.name ?? `UOM ${firstLine?.uomId ?? 0}`,
+          uomName: uom?.name ?? resolveUomName(firstLine?.uomId, uoms),
           qty: firstLine?.qty ?? 0,
           freeQty: firstLine?.freeQty ?? 0,
         } satisfies FreeIssueRow
@@ -146,11 +149,13 @@ export default function NewFreeIssuePage() {
 
   function selectItem(key: string, itemId: number) {
     const item = items.find((candidate) => candidate.itemId === itemId)
+    allowedUoms.load(itemId)
     updateLine(key, { itemId, uomId: item?.baseUomId ?? 0 })
   }
 
   function selectEditingItem(key: string, itemId: number) {
     const item = items.find((candidate) => candidate.itemId === itemId)
+    allowedUoms.load(itemId)
     updateEditingLine(key, { itemId, uomId: item?.baseUomId ?? 0 })
   }
 
@@ -325,7 +330,7 @@ export default function NewFreeIssuePage() {
                           <SelectValue placeholder="UOM" />
                         </SelectTrigger>
                         <SelectContent>
-                          {uoms.map((u) => (
+                          {pickerOptions(allowedUoms.get(line.itemId), uoms).map((u) => (
                             <SelectItem key={u.uomId} value={String(u.uomId)}>
                               {u.name}
                             </SelectItem>
@@ -390,7 +395,7 @@ export default function NewFreeIssuePage() {
                           <SelectValue placeholder="UOM" />
                         </SelectTrigger>
                         <SelectContent>
-                          {uoms.map((u) => (
+                          {pickerOptions(allowedUoms.get(line.itemId), uoms).map((u) => (
                             <SelectItem key={u.uomId} value={String(u.uomId)}>
                               {u.name}
                             </SelectItem>

Frontend/erp-system/app/dashboard/sales/invoices/[id]/page.tsx

@@ -3,7 +3,7 @@
 import { use, useEffect, useMemo, useState } from "react"
 import Link from "next/link"
 import { useRouter } from "next/navigation"
-import { ArrowLeft, Minus, Plus, Printer, Save, Send, X } from "lucide-react"
+import { ArrowLeft, ExternalLink, Minus, Plus, Printer, Save, Send, X } from "lucide-react"
 
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
@@ -11,6 +11,8 @@ import { itemsApi } from "@/lib/api/items"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage } from "@/lib/error-map"
+import { basePreview, pickerOptions, uomName } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { cn } from "@/lib/utils"
 import { getSuggestedUnitPrice } from "@/lib/sales-line-utils"
 import { Customer } from "@/types/customers"
@@ -75,6 +77,7 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
   const [error, setError] = useState<string | null>(null)
   const [saving, setSaving] = useState(false)
   const [busy, setBusy] = useState<"post" | "cancel" | null>(null)
+  const allowedUoms = useAllowedUoms()
 
   useEffect(() => {
     if (!Number.isFinite(invoiceId)) {
@@ -99,6 +102,9 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
         setCustomerId(doc.data.customerId)
         setWarehouseId(doc.data.warehouseId)
         setInvoiceType(doc.data.invoiceType)
+        // Preload allowed units for the items already on the document, so editing an
+        // existing line offers the narrowed list immediately.
+        doc.data.lines.forEach((line) => allowedUoms.load(line.itemId))
         setLines(
           doc.data.lines.map((line) => ({
             key: String(line.salesInvoiceLineId),
@@ -150,6 +156,7 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
 
   function selectItem(key: string, itemId: number) {
     const item = items.find((candidate) => candidate.itemId === itemId)
+    allowedUoms.load(itemId)
     updateLine(key, {
       itemId,
       uomId: item?.baseUomId ?? 0,
@@ -157,6 +164,11 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
     })
   }
 
+  function resolveLineUnitPrice(line: Line): number | null {
+    if (line.unitPrice !== null && line.unitPrice !== undefined) return Number(line.unitPrice)
+    return getSuggestedUnitPrice(items, line.itemId)
+  }
+
   function addLine() {
     setLines((prev) => [...prev, { ...blankLine(`line-${Date.now()}`), warehouseId: warehouseId ?? 0 }])
   }
@@ -181,14 +193,14 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
           customerId,
           warehouseId,
           invoiceType,
-          lines: lines.map((line) => ({
-            itemId: Number(line.itemId),
-            uomId: Number(line.uomId),
-            warehouseId: Number(line.warehouseId),
-            qty: Number(line.qty),
-            freeQty: Number(line.freeQty),
-            unitPrice: line.unitPrice === null ? null : Number(line.unitPrice),
-            allowManualPriceOverride: line.allowManualPriceOverride,
+            lines: lines.map((line) => ({
+              itemId: Number(line.itemId),
+              uomId: Number(line.uomId),
+              warehouseId: Number(line.warehouseId),
+              qty: Number(line.qty),
+              freeQty: Number(line.freeQty),
+              unitPrice: resolveLineUnitPrice(line),
+              allowManualPriceOverride: line.allowManualPriceOverride,
             discountMode: line.discountMode,
             discountPct: Number(line.discountPct),
             discountAmount: Number(line.discountAmount),
@@ -309,7 +321,6 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
             <div className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">Warehouse</div>
             <div className="mt-2 font-semibold text-foreground">{warehouse?.name ?? `#${invoice.warehouseId}`}</div>
             <div className="text-sm text-muted-foreground">Code: {warehouse?.code ?? invoice.warehouseId}</div>
-            <div className="text-sm text-muted-foreground">Location: {warehouse?.location ?? "—"}</div>
           </div>
           <div>
             <div className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">Totals</div>
@@ -349,7 +360,7 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
                     <div className="font-medium text-foreground">{line.description}</div>
                     <div className="text-xs text-muted-foreground">SKU {items.find((i) => i.itemId === line.itemId)?.sku ?? `#${line.itemId}`}</div>
                   </td>
-                  <td className="px-4 py-3">{uoms.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}</td>
+                  <td className="px-4 py-3">{uomName(line.uomId, uoms)}</td>
                   <td className="px-4 py-3 text-right">{line.qty.toFixed(0)}</td>
                   <td className="px-4 py-3 text-right">{line.freeQty > 0 ? line.freeQty.toFixed(0) : "—"}</td>
                   <td className="px-4 py-3 text-right">{money.format(line.unitPrice)}</td>
@@ -379,8 +390,19 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
         {invoice.status === "Draft" && postingCheck && !postingCheck.canPost ? (
           <div className="border-t pt-5">
             <div className="rounded-lg border border-amber-200 bg-amber-50 p-4 text-sm text-amber-900">
-              <div className="font-semibold">Stock shortage detected before posting</div>
-              <div className="mt-1 text-sm">The invoice cannot be posted until every line has enough available stock in the selected warehouse.</div>
+              <div className="flex flex-col gap-3 md:flex-row md:items-start md:justify-between">
+                <div>
+                  <div className="font-semibold">Stock shortage detected before posting</div>
+                  <div className="mt-1 text-sm">The invoice cannot be posted until every line has enough available stock in the selected warehouse.</div>
+                </div>
+                <Link
+                  href="/dashboard/receiving/grn/new"
+                  className="inline-flex h-9 items-center gap-2 self-start rounded-full border border-amber-300 bg-white px-4 text-sm font-medium text-amber-950 shadow-sm hover:bg-amber-100"
+                >
+                  <ExternalLink className="size-4" />
+                  Create GRN
+                </Link>
+              </div>
               <div className="mt-3 overflow-x-auto">
                 <table className="w-full text-sm">
                   <thead className="text-left text-xs uppercase tracking-wide text-amber-900/70">
@@ -433,6 +455,15 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
                   <Save className="size-4" />
                   {saving ? "Saving..." : "Save invoice"}
                 </button>
+                {postingCheck && !postingCheck.canPost ? (
+                  <Link
+                    href="/dashboard/receiving/grn/new"
+                    className="inline-flex h-9 items-center gap-2 rounded-full border border-amber-300 bg-white px-4 text-sm font-medium text-amber-950 shadow-sm hover:bg-amber-100"
+                  >
+                    <ExternalLink className="size-4" />
+                    Resolve stock in GRN
+                  </Link>
+                ) : null}
                 <button type="button" onClick={post} disabled={!canPost} className="inline-flex h-9 items-center gap-2 rounded-full bg-black px-4 text-sm font-medium text-white shadow-sm hover:bg-black/90 disabled:cursor-not-allowed disabled:opacity-40">
                   <Send className="size-4" />
                   {postingCheck && !postingCheck.canPost ? "Resolve shortages first" : busy === "post" ? "Posting..." : "Post invoice"}
@@ -479,7 +510,7 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
                             className="h-10 w-full rounded-lg border border-input bg-background px-3 text-sm"
                           >
                             <option value="">UOM</option>
-                            {uoms.map((u) => (
+                            {pickerOptions(allowedUoms.get(line.itemId), uoms).map((u) => (
                               <option key={u.uomId} value={String(u.uomId)}>
                                 {u.name}
                               </option>
@@ -495,17 +526,22 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
                             onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) || 0 })}
                             className="h-10 w-full rounded-lg border border-input bg-background px-3 text-right font-mono tabular-nums text-sm"
                           />
+                          {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? []) && (
+                            <p className="mt-1 text-xs text-muted-foreground">
+                              {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? [])}
+                            </p>
+                          )}
                         </td>
                         <td className="px-4 py-3 w-28">
-                          <input
-                            type="number"
-                            min="0"
-                            step="1"
-                            value={line.freeQty}
-                            onChange={(e) => updateLine(line.key, { freeQty: Number(e.target.value) || 0 })}
-                            className="h-10 w-full rounded-lg border border-input bg-background px-3 text-right font-mono tabular-nums text-sm"
-                          />
-                        </td>
+                        <input
+                          type="number"
+                          min="0"
+                          step="1"
+                          value={line.freeQty}
+                          onChange={(e) => updateLine(line.key, { freeQty: Number(e.target.value) || 0 })}
+                          className="h-10 w-full rounded-lg border border-input bg-background px-3 text-right font-mono tabular-nums text-sm"
+                        />
+                      </td>
                         <td className="px-4 py-3 w-32">
                           <input
                             type="number"
@@ -515,6 +551,11 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
                             onChange={(e) => updateLine(line.key, { unitPrice: e.target.value === "" ? null : Number(e.target.value) })}
                             className="h-10 w-full rounded-lg border border-input bg-background px-3 text-right font-mono tabular-nums text-sm"
                           />
+                          <div className="mt-1 text-[11px] text-muted-foreground">
+                            {getSuggestedUnitPrice(items, line.itemId) !== null
+                              ? `Suggested: ${money.format(getSuggestedUnitPrice(items, line.itemId) ?? 0)}`
+                              : "No price suggestion available"}
+                          </div>
                         </td>
                         <td className="px-4 py-3 w-24 text-right">
                     <button

Frontend/erp-system/app/dashboard/sales/invoices/[id]/print/page.tsx

@@ -7,6 +7,7 @@ import { ArrowLeft, Printer } from "lucide-react"
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
 import { itemsApi } from "@/lib/api/items"
+import { uomName } from "@/lib/uom"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage } from "@/lib/error-map"
@@ -143,7 +144,7 @@ export default function SalesInvoicePrintPage({ params }: { params: { id: string
                     <div className="font-medium text-foreground">{line.description}</div>
                     <div className="text-xs text-muted-foreground">SKU {items.find((i) => i.itemId === line.itemId)?.sku ?? `#${line.itemId}`}</div>
                   </TableCell>
-                  <TableCell>{uoms.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}</TableCell>
+                  <TableCell>{uomName(line.uomId, uoms)}</TableCell>
                   <TableCell className="text-right">{line.qty.toFixed(2)}</TableCell>
                   <TableCell className="text-right">{line.freeQty > 0 ? line.freeQty.toFixed(2) : "—"}</TableCell>
                   <TableCell className="text-right">{line.unitPrice.toFixed(2)}</TableCell>

Frontend/erp-system/app/dashboard/sales/invoices/new/page.tsx

@@ -12,6 +12,8 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@
 import { Badge } from "@/components/ui/badge"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { cn } from "@/lib/utils"
+import { basePreview, pickerOptions } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { getSuggestedUnitPrice } from "@/lib/sales-line-utils"
 import { errorMessage } from "@/lib/error-map"
 import { salesApi } from "@/lib/api/sales"
@@ -71,6 +73,7 @@ export default function NewSalesInvoicePage() {
   const [loading, setLoading] = useState(true)
   const [submitError, setSubmitError] = useState<string | null>(null)
   const [saving, setSaving] = useState(false)
+  const allowedUoms = useAllowedUoms()
 
   useEffect(() => {
     Promise.all([
@@ -129,6 +132,9 @@ export default function NewSalesInvoicePage() {
 
   function selectItem(key: string, itemId: number) {
     const item = items.find((candidate) => candidate.itemId === itemId)
+    // Load the units this item can actually be sold in, so the UOM picker below narrows from
+    // the global list to base + defined conversions.
+    allowedUoms.load(itemId)
     updateLine(key, {
       itemId,
       uomId: item?.baseUomId ?? 0,
@@ -363,7 +369,7 @@ export default function NewSalesInvoicePage() {
                           <SelectValue placeholder="UOM" />
                         </SelectTrigger>
                         <SelectContent>
-                          {uoms.map((u) => (
+                          {pickerOptions(allowedUoms.get(line.itemId), uoms).map((u) => (
                             <SelectItem key={u.uomId} value={String(u.uomId)}>
                               {u.name}
                             </SelectItem>
@@ -380,6 +386,12 @@ export default function NewSalesInvoicePage() {
                         onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })}
                         className="h-9 w-24 text-right font-mono text-sm tabular-nums"
                       />
+                      {/* Makes the conversion visible while editing instead of at post time. */}
+                      {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? []) && (
+                        <p className="mt-1 text-xs text-muted-foreground">
+                          {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? [])}
+                        </p>
+                      )}
                     </TableCell>
                     <TableCell className="px-4 py-2">
                       <Input
@@ -400,6 +412,11 @@ export default function NewSalesInvoicePage() {
                         onChange={(e) => updateLine(line.key, { unitPrice: e.target.value === "" ? null : Number(e.target.value) })}
                         className="h-9 w-28 text-right font-mono text-sm tabular-nums"
                       />
+                      <div className="mt-1 text-[11px] text-muted-foreground">
+                        {getSuggestedUnitPrice(items, line.itemId) !== null
+                          ? `Suggested: ${lkr.format(getSuggestedUnitPrice(items, line.itemId) ?? 0)}`
+                          : "No price suggestion available"}
+                      </div>
                     </TableCell>
                     <TableCell className="px-4 py-2">
                       <Input

Frontend/erp-system/app/dashboard/sales/reports/[reportId]/page.tsx

@@ -20,7 +20,7 @@ function formatHeader(key: string) {
     .trim()
 }
 
-function formatCell(value: unknown) {
+function formatCell(value: unknown): string {
   if (value === null || value === undefined) return ""
   if (typeof value === "number") return value.toLocaleString("en-LK", { maximumFractionDigits: 2 })
   if (typeof value === "string") {

Frontend/erp-system/app/dashboard/sales/slips/[id]/page.tsx

@@ -2,11 +2,13 @@
 
 import { use, useEffect, useMemo, useState } from "react"
 import Link from "next/link"
-import { ArrowLeft, Minus, Plus, Printer, Save, Send, X } from "lucide-react"
+import { ArrowLeft, ExternalLink, Minus, Plus, Printer, Save, Send, X } from "lucide-react"
 
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
 import { itemsApi } from "@/lib/api/items"
+import { basePreview, pickerOptions, uomName } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { usersApi } from "@/lib/api/users"
@@ -71,6 +73,7 @@ export default function SalesSlipDetailPage({ params }: { params: Promise<{ id:
   const [error, setError] = useState<string | null>(null)
   const [saving, setSaving] = useState(false)
   const [actionBusy, setActionBusy] = useState<"post" | "cancel" | null>(null)
+  const allowedUoms = useAllowedUoms()
 
   useEffect(() => {
     if (!Number.isFinite(slipId)) {
@@ -97,6 +100,7 @@ export default function SalesSlipDetailPage({ params }: { params: Promise<{ id:
         setWarehouseId(doc.data.warehouseId)
         setCashierUserId(doc.data.cashierUserId)
         setPromotionSuggestion(null)
+        doc.data.lines.forEach((line) => allowedUoms.load(line.itemId))
         setLines(
           doc.data.lines.map((line) => ({
             key: String(line.salesSlipLineId),
@@ -149,12 +153,21 @@ export default function SalesSlipDetailPage({ params }: { params: Promise<{ id:
   }
 
   function selectItem(key: string, itemId: number) {
+    allowedUoms.load(itemId)
     updateLine(key, {
       itemId,
+      // Reset to the new item's base unit: a UOM carried over from the previous item
+      // usually has no conversion for this one, and would be refused on save.
+      uomId: items.find((i) => i.itemId === itemId)?.baseUomId ?? 0,
       unitPrice: getSuggestedUnitPrice(items, itemId),
     })
   }
 
+  function resolveLineUnitPrice(line: Line): number | null {
+    if (line.unitPrice !== null && line.unitPrice !== undefined) return Number(line.unitPrice)
+    return getSuggestedUnitPrice(items, line.itemId)
+  }
+
   function addLine() {
     setLines((prev) => [...prev, blankLine(`line-${Date.now()}`)])
   }
@@ -172,14 +185,14 @@ export default function SalesSlipDetailPage({ params }: { params: Promise<{ id:
         customerId,
         warehouseId,
         cashierUserId,
-        lines: lines.map((line) => ({
-          itemId: Number(line.itemId),
-          uomId: Number(line.uomId),
-          warehouseId: Number(line.warehouseId),
-          qty: Number(line.qty),
-          freeQty: Number(line.freeQty),
-          unitPrice: line.unitPrice === null ? null : Number(line.unitPrice),
-          allowManualPriceOverride: line.allowManualPriceOverride,
+          lines: lines.map((line) => ({
+            itemId: Number(line.itemId),
+            uomId: Number(line.uomId),
+            warehouseId: Number(line.warehouseId),
+            qty: Number(line.qty),
+            freeQty: Number(line.freeQty),
+            unitPrice: resolveLineUnitPrice(line),
+            allowManualPriceOverride: line.allowManualPriceOverride,
           discountMode: line.discountMode,
           discountPct: Number(line.discountPct),
           discountAmount: Number(line.discountAmount),
@@ -335,10 +348,15 @@ export default function SalesSlipDetailPage({ params }: { params: Promise<{ id:
                   <TableCell className="px-4 py-3">
                     <div className="font-medium text-foreground">{line.description}</div>
                     <div className="text-xs text-muted-foreground">SKU {items.find((i) => i.itemId === line.itemId)?.sku ?? `#${line.itemId}`}</div>
+                    <div className="mt-1 text-[11px] text-muted-foreground">
+                      {getSuggestedUnitPrice(items, line.itemId) !== null
+                        ? `Suggested: ${money.format(getSuggestedUnitPrice(items, line.itemId) ?? 0)}`
+                        : "No price suggestion available"}
+                    </div>
                   </TableCell>
-                  <TableCell className="px-4 py-3">{uoms.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}</TableCell>
+                  <TableCell className="px-4 py-3">{uomName(line.uomId, uoms)}</TableCell>
                   <TableCell className="px-4 py-3 text-right">{line.qty.toFixed(0)}</TableCell>
-                  <TableCell className="px-4 py-3 text-right">{line.freeQty > 0 ? line.freeQty.toFixed(0) : "—"}</TableCell>
+                  <TableCell className="px-4 py-3 text-right">{line.freeQty > 0 ? line.freeQty.toFixed(0) : "-"}</TableCell>
                   <TableCell className="px-4 py-3 text-right">{money.format(line.unitPrice)}</TableCell>
                   <TableCell className="px-4 py-3 text-right font-medium">{money.format(line.lineTotal)}</TableCell>
                 </TableRow>
@@ -350,8 +368,19 @@ export default function SalesSlipDetailPage({ params }: { params: Promise<{ id:
 
       {slip.status === "Draft" && postingCheck && !postingCheck.canPost ? (
         <div className="rounded-lg border border-amber-200 bg-amber-50 p-4 text-sm text-amber-900">
-          <div className="font-semibold">Stock shortage detected before posting</div>
-          <div className="mt-1">This slip cannot be posted until every line has enough available stock in the selected warehouse.</div>
+          <div className="flex flex-col gap-3 md:flex-row md:items-start md:justify-between">
+            <div>
+              <div className="font-semibold">Stock shortage detected before posting</div>
+              <div className="mt-1">This slip cannot be posted until every line has enough available stock in the selected warehouse.</div>
+            </div>
+            <Link
+              href="/dashboard/receiving/grn/new"
+              className="inline-flex h-9 items-center gap-2 self-start rounded-full border border-amber-300 bg-white px-4 text-sm font-medium text-amber-950 shadow-sm hover:bg-amber-100"
+            >
+              <ExternalLink className="size-4" />
+              Create GRN
+            </Link>
+          </div>
           <div className="mt-3 overflow-x-auto">
             <table className="w-full text-sm">
               <thead className="text-left text-xs uppercase tracking-wide text-amber-900/70">
@@ -436,10 +465,15 @@ export default function SalesSlipDetailPage({ params }: { params: Promise<{ id:
                     <TableCell>
                       <Select value={line.uomId ? String(line.uomId) : ""} onValueChange={(v) => updateLine(line.key, { uomId: Number(v) })} disabled={locked}>
                         <SelectTrigger className="h-11!"><SelectValue placeholder="UOM" /></SelectTrigger>
-                        <SelectContent>{uoms.map((u) => <SelectItem key={u.uomId} value={String(u.uomId)}>{u.name}</SelectItem>)}</SelectContent>
+                        <SelectContent>{pickerOptions(allowedUoms.get(line.itemId), uoms).map((u) => <SelectItem key={u.uomId} value={String(u.uomId)}>{u.name}</SelectItem>)}</SelectContent>
                       </Select>
                     </TableCell>
-                    <TableCell><Input type="number" min="0" step="0.01" value={line.qty} onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })} disabled={locked} /></TableCell>
+                    <TableCell>
+                      <Input type="number" min="0" step="0.01" value={line.qty} onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })} disabled={locked} />
+                      {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? []) && (
+                        <p className="mt-1 text-xs text-muted-foreground">{basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? [])}</p>
+                      )}
+                    </TableCell>
                     <TableCell><Input type="number" min="0" step="0.01" value={line.freeQty} onChange={(e) => updateLine(line.key, { freeQty: Number(e.target.value) })} disabled={locked} /></TableCell>
                     <TableCell><Input type="number" min="0" step="0.01" value={line.unitPrice ?? ""} onChange={(e) => updateLine(line.key, { unitPrice: e.target.value === "" ? null : Number(e.target.value) })} disabled={locked} /></TableCell>
                     <TableCell><Button type="button" variant="ghost" size="icon" onClick={() => removeLine(line.key)} disabled={locked}><Minus className="size-4" /></Button></TableCell>

Frontend/erp-system/app/dashboard/sales/slips/new/page.tsx

@@ -12,6 +12,8 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@
 import { Badge } from "@/components/ui/badge"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { cn } from "@/lib/utils"
+import { basePreview, pickerOptions } from "@/lib/uom"
+import { useAllowedUoms } from "@/hooks/use-allowed-uoms"
 import { getSuggestedUnitPrice } from "@/lib/sales-line-utils"
 import { errorMessage } from "@/lib/error-map"
 import { salesApi } from "@/lib/api/sales"
@@ -65,6 +67,7 @@ export default function NewSalesSlipPage() {
   const [lines, setLines] = useState<Line[]>([blankLine("line-1")])
   const [loading, setLoading] = useState(true)
   const [submitError, setSubmitError] = useState<string | null>(null)
+  const allowedUoms = useAllowedUoms()
   const [saving, setSaving] = useState(false)
 
   useEffect(() => {
@@ -104,6 +107,8 @@ export default function NewSalesSlipPage() {
 
   function selectItem(key: string, itemId: number) {
     const item = items.find((candidate) => candidate.itemId === itemId)
+    // Narrow the UOM picker to units this item has a conversion for.
+    allowedUoms.load(itemId)
     updateLine(key, {
       itemId,
       uomId: item?.baseUomId ?? 0,
@@ -111,6 +116,11 @@ export default function NewSalesSlipPage() {
     })
   }
 
+  function resolveLineUnitPrice(line: Line): number | null {
+    if (line.unitPrice !== null && line.unitPrice !== undefined) return Number(line.unitPrice)
+    return getSuggestedUnitPrice(items, line.itemId)
+  }
+
   function addLine() {
     setLines((prev) => [...prev, blankLine(`line-${Date.now()}`)])
   }
@@ -162,7 +172,7 @@ export default function NewSalesSlipPage() {
         warehouseId: Number(line.warehouseId),
         qty: Number(line.qty),
         freeQty: Number(line.freeQty),
-        unitPrice: line.unitPrice === null ? null : Number(line.unitPrice),
+        unitPrice: resolveLineUnitPrice(line),
         allowManualPriceOverride: line.allowManualPriceOverride,
         discountMode: line.discountMode,
         discountPct: Number(line.discountPct),
@@ -329,7 +339,7 @@ export default function NewSalesSlipPage() {
                           <SelectValue placeholder="UOM" />
                         </SelectTrigger>
                         <SelectContent>
-                          {uoms.map((u) => (
+                          {pickerOptions(allowedUoms.get(line.itemId), uoms).map((u) => (
                             <SelectItem key={u.uomId} value={String(u.uomId)}>
                               {u.name}
                             </SelectItem>
@@ -346,6 +356,12 @@ export default function NewSalesSlipPage() {
                         onChange={(e) => updateLine(line.key, { qty: Number(e.target.value) })}
                         className="h-9 w-24 text-right font-mono text-sm tabular-nums"
                       />
+                      {/* Makes the conversion visible while editing instead of at post time. */}
+                      {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? []) && (
+                        <p className="mt-1 text-xs text-muted-foreground">
+                          {basePreview(line.qty, line.uomId, allowedUoms.get(line.itemId) ?? [])}
+                        </p>
+                      )}
                     </TableCell>
                     <TableCell className="px-4 py-2">
                       <Input
@@ -366,6 +382,11 @@ export default function NewSalesSlipPage() {
                         onChange={(e) => updateLine(line.key, { unitPrice: e.target.value === "" ? null : Number(e.target.value) })}
                         className="h-9 w-28 text-right font-mono text-sm tabular-nums"
                       />
+                      <div className="mt-1 text-[11px] text-muted-foreground">
+                        {getSuggestedUnitPrice(items, line.itemId) !== null
+                          ? `Suggested: ${lkr.format(getSuggestedUnitPrice(items, line.itemId) ?? 0)}`
+                          : "No price suggestion available"}
+                      </div>
                     </TableCell>
                     <TableCell className="px-4 py-2">
                       <Input

Frontend/erp-system/app/dashboard/settings/company-profile/page.tsx

@@ -1,135 +1,22 @@
-"use client"
-
-import { useEffect, useState } from "react"
 import Link from "next/link"
-import { ArrowLeft, Building2, Save } from "lucide-react"
+import { Building2 } from "lucide-react"
 
-import { companyApi } from "@/lib/api/company"
-import { errorMessage } from "@/lib/error-map"
+import { buttonVariants } from "@/components/ui/button"
 import { cn } from "@/lib/utils"
-import { CompanyProfile } from "@/types/company"
-
-import { buttonVariants, Button } from "@/components/ui/button"
-import { Input } from "@/components/ui/input"
-import { Label } from "@/components/ui/label"
-import { Skeleton } from "@/components/ui/skeleton"
-import { toast } from "@/components/ui/toast"
 
 export default function CompanyProfilePage() {
-  const [profile, setProfile] = useState<CompanyProfile | null>(null)
-  const [etag, setEtag] = useState<string | null>(null)
-  const [error, setError] = useState<string | null>(null)
-  const [saving, setSaving] = useState(false)
-
-  useEffect(() => {
-    companyApi
-      .getProfile()
-      .then((res) => {
-        setProfile(res.data)
-        setEtag(res.etag)
-      })
-      .catch((err) => setError(errorMessage(err)))
-  }, [])
-
-  function patch<K extends keyof CompanyProfile>(key: K, value: CompanyProfile[K]) {
-    setProfile((prev) => (prev ? { ...prev, [key]: value } : prev))
-  }
-
-  async function save() {
-    if (!profile || !etag) return
-    setSaving(true)
-    setError(null)
-    try {
-      const updated = await companyApi.updateProfile(profile, etag)
-      setProfile(updated.data)
-      setEtag(updated.etag)
-      toast.success("Company profile saved", updated.data.legalName)
-    } catch (err) {
-      setError(errorMessage(err))
-    } finally {
-      setSaving(false)
-    }
-  }
-
   return (
     <div className="flex flex-col gap-6">
-      <div className="flex items-center gap-3">
-        <Link href="/dashboard/settings" className={cn(buttonVariants({ variant: "ghost", size: "icon-lg" }))}>
-          <ArrowLeft className="size-5" />
-        </Link>
+      <div className="flex flex-col items-center justify-center gap-4 rounded-2xl border p-12 text-center">
+        <Building2 className="size-10 text-muted-foreground" />
         <div>
-          <h1 className="text-2xl font-bold text-foreground">Company Profile</h1>
-          <p className="text-base text-muted-foreground">Invoice header, tax details, logo, and bank information.</p>
+          <h1 className="text-xl font-semibold text-foreground">Company Profile</h1>
+          <p className="text-base text-muted-foreground">This feature is not available yet.</p>
         </div>
+        <Link href="/dashboard/settings" className={cn(buttonVariants({ variant: "outline", size: "lg" }))}>
+          Back to Settings
+        </Link>
       </div>
-
-      {error && <div className="rounded-lg border border-destructive/30 bg-destructive/5 p-5 text-base text-destructive">{error}</div>}
-      {!error && !profile && <Skeleton className="h-64 w-full" />}
-
-      {!error && profile && (
-        <div className="flex flex-col gap-6 rounded-2xl border p-6">
-          <div className="flex items-center gap-2">
-            <Building2 className="size-5 text-primary" />
-            <h2 className="text-lg font-semibold">Invoice Header</h2>
-          </div>
-
-          <div className="grid gap-4 md:grid-cols-2">
-            <Field label="Legal Name" value={profile.legalName} onChange={(v) => patch("legalName", v)} />
-            <Field label="Trade Name" value={profile.tradeName ?? ""} onChange={(v) => patch("tradeName", v)} />
-            <Field label="Logo URL" value={profile.logoUrl ?? ""} onChange={(v) => patch("logoUrl", v)} />
-            <Field label="Tax Registration No" value={profile.taxRegistrationNo ?? ""} onChange={(v) => patch("taxRegistrationNo", v)} />
-            <Field label="VAT Registration No" value={profile.vatRegistrationNo ?? ""} onChange={(v) => patch("vatRegistrationNo", v)} />
-            <Field label="Phone" value={profile.phone ?? ""} onChange={(v) => patch("phone", v)} />
-            <Field label="Email" value={profile.email ?? ""} onChange={(v) => patch("email", v)} />
-            <Field label="City" value={profile.city ?? ""} onChange={(v) => patch("city", v)} />
-            <Field label="Country" value={profile.country ?? ""} onChange={(v) => patch("country", v)} />
-            <Field label="Address Line 1" value={profile.addressLine1 ?? ""} onChange={(v) => patch("addressLine1", v)} />
-            <Field label="Address Line 2" value={profile.addressLine2 ?? ""} onChange={(v) => patch("addressLine2", v)} />
-          </div>
-
-          <div className="border-t" />
-
-          <div className="flex items-center gap-2">
-            <Save className="size-5 text-primary" />
-            <h2 className="text-lg font-semibold">Bank Details</h2>
-          </div>
-
-          <div className="grid gap-4 md:grid-cols-2">
-            <Field label="Bank Name" value={profile.bankName ?? ""} onChange={(v) => patch("bankName", v)} />
-            <Field label="Bank Branch" value={profile.bankBranch ?? ""} onChange={(v) => patch("bankBranch", v)} />
-            <Field label="Account Name" value={profile.accountName ?? ""} onChange={(v) => patch("accountName", v)} />
-            <Field label="Account Number" value={profile.accountNumber ?? ""} onChange={(v) => patch("accountNumber", v)} />
-            <Field label="SWIFT Code" value={profile.swiftCode ?? ""} onChange={(v) => patch("swiftCode", v)} />
-            <Field label="Footer Note" value={profile.footerNote ?? ""} onChange={(v) => patch("footerNote", v)} />
-          </div>
-
-          <div className="flex justify-end gap-3">
-            <Link href="/dashboard/settings" className={cn(buttonVariants({ variant: "outline", size: "lg" }))}>
-              Cancel
-            </Link>
-            <Button size="lg" onClick={save} disabled={saving}>
-              {saving ? "Saving..." : "Save Profile"}
-            </Button>
-          </div>
-        </div>
-      )}
-    </div>
-  )
-}
-
-function Field({
-  label,
-  value,
-  onChange,
-}: {
-  label: string
-  value: string
-  onChange: (value: string) => void
-}) {
-  return (
-    <div className="flex flex-col gap-2">
-      <Label>{label}</Label>
-      <Input value={value} onChange={(e) => onChange(e.target.value)} />
     </div>
   )
 }

Frontend/erp-system/app/dashboard/stock/enquiry/page.tsx

@@ -7,6 +7,7 @@ import { PackageSearch, Search } from "lucide-react"
 import { stockApi } from "@/lib/api/stock"
 import { itemsApi } from "@/lib/api/items"
 import { warehousesApi } from "@/lib/api/warehouses"
+import { formatQtyValue, formatQtyWithName } from "@/lib/uom"
 import { errorMessage } from "@/lib/error-map"
 import { OnHand } from "@/types/stock"
 import { ItemListItem, Warehouse } from "@/types/master-data"
@@ -135,11 +136,12 @@ export default function StockEnquiryPage() {
                     <div className="text-sm text-muted-foreground">{item?.name}</div>
                   </TableCell>
                   <TableCell className="px-3 py-3.5">{wh?.code ?? `#${row.warehouseId}`}</TableCell>
-                  <TableCell className="px-3 py-3.5">{row.onHand}</TableCell>
-                  <TableCell className="px-3 py-3.5 font-medium">{row.available}</TableCell>
-                  <TableCell className="px-3 py-3.5">{row.onHold}</TableCell>
-                  <TableCell className="px-3 py-3.5">{row.inTransit}</TableCell>
-                  <TableCell className="px-3 py-3.5">{row.reserved}</TableCell>
+                  {/* Every figure here is base UOM; the label is what tells the user which. */}
+                  <TableCell className="px-3 py-3.5">{formatQtyWithName(row.onHand, row.baseUomName)}</TableCell>
+                  <TableCell className="px-3 py-3.5 font-medium">{formatQtyWithName(row.available, row.baseUomName)}</TableCell>
+                  <TableCell className="px-3 py-3.5">{formatQtyValue(row.onHold)}</TableCell>
+                  <TableCell className="px-3 py-3.5">{formatQtyValue(row.inTransit)}</TableCell>
+                  <TableCell className="px-3 py-3.5">{formatQtyValue(row.reserved)}</TableCell>
                   <TableCell className="px-3 py-3.5">
                     <Link
                       href={`/dashboard/stock/valuation?itemId=${row.itemId}&warehouseId=${row.warehouseId}`}

Frontend/erp-system/app/dashboard/stock/ledger/page.tsx

@@ -6,6 +6,7 @@ import { ChevronLeft, ChevronRight, ScrollText } from "lucide-react"
 import { stockApi } from "@/lib/api/stock"
 import { itemsApi } from "@/lib/api/items"
 import { warehousesApi } from "@/lib/api/warehouses"
+import { formatQtyWithName } from "@/lib/uom"
 import { errorMessage } from "@/lib/error-map"
 import { cn } from "@/lib/utils"
 import { LedgerEntry } from "@/types/stock"
@@ -189,10 +190,10 @@ export default function StockLedgerPage() {
                         {entry.direction}
                       </Badge>
                     </TableCell>
-                    <TableCell className="px-3 py-3.5">{entry.qtyBase}</TableCell>
+                    <TableCell className="px-3 py-3.5">{formatQtyWithName(entry.qtyBase, entry.baseUomName)}</TableCell>
                     <TableCell className="px-3 py-3.5">{entry.unitCost.toFixed(2)}</TableCell>
                     <TableCell className="px-3 py-3.5">{entry.value.toFixed(2)}</TableCell>
-                    <TableCell className="px-3 py-3.5 font-medium">{entry.runningBalance}</TableCell>
+                    <TableCell className="px-3 py-3.5 font-medium">{formatQtyWithName(entry.runningBalance, entry.baseUomName)}</TableCell>
                     <TableCell className="px-3 py-3.5 text-muted-foreground">
                       {entry.sourceDocType} #{entry.sourceDocId}
                     </TableCell>

Frontend/erp-system/app/dashboard/stock/page.tsx

@@ -1,69 +1,3 @@
-import Link from "next/link"
-import {
-  AlertOctagon,
-  AlertTriangle,
-  ArrowLeftRight,
-  BadgeDollarSign,
-  ClipboardList,
-  PackageSearch,
-  ScrollText,
-  SlidersHorizontal,
-  type LucideIcon,
-} from "lucide-react"
-
-import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card"
-
-const areas: { title: string; description: string; href: string; icon: LucideIcon }[] = [
-  {
-    title: "Stock Enquiry",
-    description: "On-hand, available, on-hold, and in-transit quantities by item and warehouse.",
-    href: "/dashboard/stock/enquiry",
-    icon: PackageSearch,
-  },
-  {
-    title: "Stock Ledger",
-    description: "The immutable, append-only movement journal — every in/out with running balance.",
-    href: "/dashboard/stock/ledger",
-    icon: ScrollText,
-  },
-  {
-    title: "Valuation",
-    description: "FIFO cost-layer breakdown and total stock value by item and warehouse.",
-    href: "/dashboard/stock/valuation",
-    icon: BadgeDollarSign,
-  },
-  {
-    title: "Transfers",
-    description: "Move stock between warehouses: create, dispatch, and receive (in-transit).",
-    href: "/dashboard/stock/transfers",
-    icon: ArrowLeftRight,
-  },
-  {
-    title: "Adjustments",
-    description: "Increase, decrease, or write off stock with a mandatory reason code.",
-    href: "/dashboard/stock/adjustments",
-    icon: SlidersHorizontal,
-  },
-  {
-    title: "Counts",
-    description: "Cycle or full physical counts — snapshot, enter counts, post variance.",
-    href: "/dashboard/stock/counts",
-    icon: ClipboardList,
-  },
-  {
-    title: "Reorder Alerts",
-    description: "Items at or below their reorder point, with a one-click requisition.",
-    href: "/dashboard/stock/reorder-alerts",
-    icon: AlertTriangle,
-  },
-  {
-    title: "Wastage",
-    description: "Damage, theft/loss, and expiry write-offs — reason-coded adjustments with a totals report.",
-    href: "/dashboard/stock/wastage",
-    icon: AlertOctagon,
-  },
-]
-
 export default function StockHubPage() {
   return (
     <div className="flex flex-col gap-6">
@@ -73,26 +7,6 @@ export default function StockHubPage() {
           FIFO-costed stock across multiple warehouses (FR-STK-01..14).
         </p>
       </div>
-
-      <div className="grid grid-cols-1 gap-4 sm:grid-cols-2 xl:grid-cols-3">
-        {areas.map((area) => (
-          <Link key={area.href} href={area.href}>
-            <Card className="h-full transition-shadow hover:shadow-md">
-              <CardHeader>
-                <div className="flex items-center gap-3">
-                  <div className="flex size-11 shrink-0 items-center justify-center rounded-xl bg-primary/10 text-primary">
-                    <area.icon className="size-5" />
-                  </div>
-                  <CardTitle className="text-lg">{area.title}</CardTitle>
-                </div>
-              </CardHeader>
-              <CardContent>
-                <p className="text-base text-muted-foreground">{area.description}</p>
-              </CardContent>
-            </Card>
-          </Link>
-        ))}
-      </div>
     </div>
   )
 }

Frontend/erp-system/app/dashboard/stock/reorder-alerts/page.tsx

@@ -6,9 +6,11 @@ import { AlertTriangle, CheckCircle2 } from "lucide-react"
 import { stockApi } from "@/lib/api/stock"
 import { itemsApi } from "@/lib/api/items"
 import { warehousesApi } from "@/lib/api/warehouses"
+import { uomsApi } from "@/lib/api/uoms"
 import { errorMessage } from "@/lib/error-map"
+import { formatQty } from "@/lib/uom"
 import { ReorderAlert } from "@/types/stock"
-import { ItemListItem, Warehouse } from "@/types/master-data"
+import { ItemListItem, Uom, Warehouse } from "@/types/master-data"
 
 import { Button } from "@/components/ui/button"
 import { Skeleton } from "@/components/ui/skeleton"
@@ -19,16 +21,23 @@ export default function ReorderAlertsPage() {
   const [alerts, setAlerts] = useState<ReorderAlert[] | null>(null)
   const [items, setItems] = useState<ItemListItem[] | null>(null)
   const [warehouses, setWarehouses] = useState<Warehouse[] | null>(null)
+  const [uoms, setUoms] = useState<Uom[]>([])
   const [error, setError] = useState<string | null>(null)
   const [requesting, setRequesting] = useState<string | null>(null)
   const [requested, setRequested] = useState<Set<string>>(new Set())
 
   useEffect(() => {
-    Promise.all([stockApi.reorderAlerts(), itemsApi.list({ pageSize: 200 }), warehousesApi.list()])
-      .then(([a, it, wh]) => {
+    Promise.all([
+      stockApi.reorderAlerts(),
+      itemsApi.list({ pageSize: 200 }),
+      warehousesApi.list(),
+      uomsApi.list({ pageSize: 200 }),
+    ])
+      .then(([a, it, wh, uo]) => {
         setAlerts(a.items)
         setItems(it.items)
         setWarehouses(wh.items)
+        setUoms(uo.items)
       })
       .catch((err) => setError(errorMessage(err)))
   }, [])
@@ -44,7 +53,10 @@ export default function ReorderAlertsPage() {
       const res = await stockApi.createReorderRequisition(alert.itemId, alert.warehouseId)
       setRequested((prev) => new Set(prev).add(key))
       const qty = res.lines[0]?.qty ?? alert.suggestedRequisitionQty
-      toast.success("Requisition created", `${res.docNo} for ${qty} units.`)
+      // Requisitions are base-UOM only, so name the item's actual base unit rather than
+      // the placeholder word "units".
+      const uom = itemsById.get(alert.itemId)?.baseUomId
+      toast.success("Requisition created", `${res.docNo} for ${formatQty(qty, uom ?? null, uoms)}.`)
     } catch (err) {
       toast.error("Could not create requisition", errorMessage(err))
     } finally {

Frontend/erp-system/app/print/sales/bundles/page.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import { useEffect, useState } from "react"
+import { Suspense, useEffect, useState } from "react"
 import { useSearchParams } from "next/navigation"
 import { Printer } from "lucide-react"
 
@@ -8,6 +8,7 @@ import { bundleApi } from "@/lib/api/bundles"
 import { errorMessage } from "@/lib/error-map"
 import { Button } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
+import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { BundleSaleSummary } from "@/types/bundles"
 
@@ -22,7 +23,7 @@ function statusClass(status: BundleSaleSummary["status"]) {
   }
 }
 
-export default function BundleBatchPrintPage() {
+function BundleBatchPrintContent() {
   const searchParams = useSearchParams()
   const status = searchParams.get("status") ?? "All"
   const query = searchParams.get("q") ?? ""
@@ -88,3 +89,11 @@ export default function BundleBatchPrintPage() {
     </div>
   )
 }
+
+export default function BundleBatchPrintPage() {
+  return (
+    <Suspense fallback={<Skeleton className="h-48 w-full" />}>
+      <BundleBatchPrintContent />
+    </Suspense>
+  )
+}

Frontend/erp-system/app/print/sales/invoices/[id]/page.tsx

@@ -6,6 +6,7 @@ import { Printer } from "lucide-react"
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
 import { itemsApi } from "@/lib/api/items"
+import { uomName } from "@/lib/uom"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage } from "@/lib/error-map"
@@ -131,7 +132,7 @@ export default function SalesInvoicePrintPage({ params }: { params: Promise<{ id
                   <div className="font-medium text-foreground">{line.description}</div>
                   <div className="text-xs text-muted-foreground">SKU {items.find((i) => i.itemId === line.itemId)?.sku ?? `#${line.itemId}`}</div>
                 </TableCell>
-                <TableCell>{uoms.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}</TableCell>
+                <TableCell>{uomName(line.uomId, uoms)}</TableCell>
                 <TableCell className="text-right">{line.qty.toFixed(2)}</TableCell>
                 <TableCell className="text-right">{line.freeQty > 0 ? line.freeQty.toFixed(2) : "—"}</TableCell>
                 <TableCell className="text-right">{line.unitPrice.toFixed(2)}</TableCell>

Frontend/erp-system/app/print/sales/invoices/page.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import { useEffect, useState } from "react"
+import { Suspense, useEffect, useState } from "react"
 import { useSearchParams } from "next/navigation"
 import { Printer } from "lucide-react"
 
@@ -8,6 +8,7 @@ import { salesApi } from "@/lib/api/sales"
 import { errorMessage } from "@/lib/error-map"
 import { Button } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
+import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { SalesInvoiceSummary } from "@/types/sales"
 
@@ -22,7 +23,7 @@ function statusClass(status: SalesInvoiceSummary["status"]) {
   }
 }
 
-export default function SalesInvoiceBatchPrintPage() {
+function SalesInvoiceBatchPrintContent() {
   const searchParams = useSearchParams()
   const status = searchParams.get("status") ?? "All"
   const query = searchParams.get("q") ?? ""
@@ -105,3 +106,11 @@ export default function SalesInvoiceBatchPrintPage() {
     </div>
   )
 }
+
+export default function SalesInvoiceBatchPrintPage() {
+  return (
+    <Suspense fallback={<Skeleton className="h-48 w-full" />}>
+      <SalesInvoiceBatchPrintContent />
+    </Suspense>
+  )
+}

Frontend/erp-system/app/print/sales/slips/[id]/page.tsx

@@ -6,6 +6,7 @@ import { Printer } from "lucide-react"
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
 import { itemsApi } from "@/lib/api/items"
+import { uomName } from "@/lib/uom"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { usersApi } from "@/lib/api/users"
@@ -123,7 +124,7 @@ export default function SalesSlipPrintPage({ params }: { params: Promise<{ id: s
                   <div className="font-medium text-foreground">{line.description}</div>
                   <div className="text-xs text-muted-foreground">SKU {items.find((i) => i.itemId === line.itemId)?.sku ?? `#${line.itemId}`}</div>
                 </TableCell>
-                <TableCell>{uoms.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}</TableCell>
+                <TableCell>{uomName(line.uomId, uoms)}</TableCell>
                 <TableCell className="text-right">{line.qty.toFixed(0)}</TableCell>
                 <TableCell className="text-right">{line.freeQty > 0 ? line.freeQty.toFixed(0) : "—"}</TableCell>
                 <TableCell className="text-right">{line.unitPrice.toFixed(2)}</TableCell>

Frontend/erp-system/app/print/sales/slips/page.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import { useEffect, useState } from "react"
+import { Suspense, useEffect, useState } from "react"
 import { useSearchParams } from "next/navigation"
 import { Printer } from "lucide-react"
 
@@ -8,6 +8,7 @@ import { salesApi } from "@/lib/api/sales"
 import { errorMessage } from "@/lib/error-map"
 import { Button } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
+import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { SalesSlipSummary } from "@/types/sales"
 
@@ -22,7 +23,7 @@ function statusClass(status: SalesSlipSummary["status"]) {
   }
 }
 
-export default function SalesSlipBatchPrintPage() {
+function SalesSlipBatchPrintContent() {
   const searchParams = useSearchParams()
   const status = searchParams.get("status") ?? "All"
   const query = searchParams.get("q") ?? ""
@@ -103,3 +104,11 @@ export default function SalesSlipBatchPrintPage() {
     </div>
   )
 }
+
+export default function SalesSlipBatchPrintPage() {
+  return (
+    <Suspense fallback={<Skeleton className="h-48 w-full" />}>
+      <SalesSlipBatchPrintContent />
+    </Suspense>
+  )
+}

Frontend/erp-system/components/Layouts/AppSidebar.tsx

@@ -4,6 +4,9 @@ import { useEffect, useState } from "react"
 import Link from "next/link"
 import { usePathname } from "next/navigation"
 import {
+  AlertOctagon,
+  AlertTriangle,
+  ArrowLeftRight,
   Banknote,
   BadgeDollarSign,
   BookOpen,
@@ -29,6 +32,7 @@ import {
   Menu,
   Package,
   PackageCheck,
+  PackageSearch,
   PackageX,
   PlayCircle,
   PieChart,
@@ -36,6 +40,7 @@ import {
   ReceiptText,
   Ruler,
   Scale,
+  ScrollText,
   Settings,
   ShieldCheck,
   ShoppingCart,
@@ -116,7 +121,26 @@ const navItems: {
     ],
   },
   { title: "Receiving", code: "receiving", href: "/dashboard/receiving/grn", icon: PackageCheck, chevron: true },
-  { title: "Stock", code: "stock", href: "/dashboard/stock", icon: Warehouse, chevron: true },
+  {
+    title: "Stock",
+    code: "stock",
+    href: "/dashboard/stock",
+    // Clicking "Stock" itself lands on Stock Ledger — the hub page underneath has nothing on
+    // it (its card grid was removed once the sidebar grew these sub-items), same as Procurement.
+    landingHref: "/dashboard/stock/ledger",
+    icon: Warehouse,
+    chevron: true,
+    children: [
+      { title: "Stock Ledger", code: "stock.ledger", href: "/dashboard/stock/ledger", icon: ScrollText },
+      { title: "Stock Enquiry", code: "stock.enquiry", href: "/dashboard/stock/enquiry", icon: PackageSearch },
+      { title: "Valuation", code: "stock.valuation", href: "/dashboard/stock/valuation", icon: BadgeDollarSign },
+      { title: "Transfers", code: "stock.transfers", href: "/dashboard/stock/transfers", icon: ArrowLeftRight },
+      { title: "Adjustments", code: "stock.adjustments", href: "/dashboard/stock/adjustments", icon: SlidersHorizontal },
+      { title: "Counts", code: "stock.counts", href: "/dashboard/stock/counts", icon: ClipboardList },
+      { title: "Reorder Alerts", code: "stock.reorder-alerts", href: "/dashboard/stock/reorder-alerts", icon: AlertTriangle },
+      { title: "Wastage", code: "stock.wastage", href: "/dashboard/stock/wastage", icon: AlertOctagon },
+    ],
+  },
   { title: "Warehouses", code: "warehouses", href: "/dashboard/warehouse", icon: Building2, chevron: true },
   { title: "Orders", code: "orders", href: "/dashboard/orders", icon: ShoppingCart, chevron: true },
   {
@@ -402,14 +426,15 @@ export function AppSidebar() {
   // flashing the full menu to a restricted role. Once resolved, a nav item
   // is visible if its own code is granted, or (for parents) if any child is.
   //
-  // "procurement", "hrm", "sales" and "production" are exempted from that check (frontend-only): no
-  // role is currently seeded with NAV:procurement/NAV:hrm/NAV:production or their children
-  // server-side, which would hide the whole section for everyone. Remove each bypass once roles are granted
-  // the permission properly (Settings → Roles → Sidebar permissions) or a backend seed
-  // grants it. This is also flagged in 02-SECURITY.md as the AR-09 sidebar-visibility
+  // "procurement", "hrm", "sales", "production" and "stock" are exempted from that check
+  // (frontend-only): no role is currently seeded with NAV:procurement/NAV:hrm/NAV:production
+  // or their children server-side (stock's children specifically have no SubNavItem rows at
+  // all yet), which would hide the whole section for everyone. Remove each bypass once roles
+  // are granted the permission properly (Settings → Roles → Sidebar permissions) or a backend
+  // seed grants it. This is also flagged in 02-SECURITY.md as the AR-09 sidebar-visibility
   // stopgap for HRM's salary/PII data — it hides HRM from the UI but doesn't enforce
   // anything server-side.
-  const bypassCodes = new Set(["procurement", "sales", "hrm", "production"])
+  const bypassCodes = new Set(["procurement", "sales", "hrm", "production", "stock"])
   const visibleItems = loading
     ? []
     : navItems

Frontend/erp-system/components/Layouts/Header.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import { useState } from "react"
+import { useEffect, useState } from "react"
 import Link from "next/link"
 import { usePathname, useRouter } from "next/navigation"
 import { ArrowLeft, Bell, LogOut, Settings, User } from "lucide-react"
@@ -165,9 +165,12 @@ export function Header() {
   const [notifications, setNotifications] = useState(initialNotifications)
   const unreadCount = notifications.filter((n) => n.unread).length
 
-  // Read after mount, not during render: localStorage doesn't exist on the server, and
-  // reading it while rendering would desync the hydration pass.
-  const [user] = useState<AuthUser | null>(() => getStoredUser())
+  // Read after mount so the first client render matches the server render.
+  const [user, setUser] = useState<AuthUser | null>(null)
+
+  useEffect(() => {
+    setUser(getStoredUser())
+  }, [])
 
   const markAllAsRead = () =>
     setNotifications((prev) => prev.map((n) => ({ ...n, unread: false })))
@@ -278,16 +281,18 @@ export function Header() {
           <DropdownMenuTrigger className="flex items-center gap-2 rounded-full py-1 pr-2 pl-1 outline-none hover:bg-muted">
             <Avatar>
               <AvatarFallback className="bg-primary/10 font-semibold text-primary">
-                {initials(displayName(user))}
+                {user ? initials(displayName(user)) : "?"}
               </AvatarFallback>
             </Avatar>
             <span className="hidden text-sm font-semibold text-foreground sm:block">
-              {displayName(user)}
+              {user ? displayName(user) : "Signed in"}
             </span>
           </DropdownMenuTrigger>
           <DropdownMenuContent align="end" className="w-80 p-2">
             <div className="px-2 py-2.5">
-              <p className="text-base font-semibold text-foreground">{displayName(user)}</p>
+              <p className="text-base font-semibold text-foreground">
+                {user ? displayName(user) : "Signed in"}
+              </p>
               {user?.email && <p className="text-sm font-normal text-muted-foreground">{user.email}</p>}
             </div>
             <DropdownMenuSeparator />

Frontend/erp-system/components/hrm/CodeNameMasterPage.tsx

@@ -8,7 +8,7 @@ import { Plus } from "lucide-react"
 
 import { errorMessage } from "@/lib/error-map"
 import { cn } from "@/lib/utils"
-import { EntityStatus, PaginationMeta } from "@/types/common"
+import { ApiResult, EntityStatus, PaginationMeta } from "@/types/common"
 
 import { Button } from "@/components/ui/button"
 import { Input } from "@/components/ui/input"
@@ -27,7 +27,7 @@ interface CodeNamed {
 
 interface Api<T extends CodeNamed> {
   list(params: { page: number; pageSize: number }): Promise<{ items: T[]; pagination: PaginationMeta }>
-  create(request: { code: string; name: string }): Promise<{ value: T }>
+  create(request: { code: string; name: string }): Promise<ApiResult<T>>
   updateStatus(id: number, status: EntityStatus): Promise<void>
 }
 

Frontend/erp-system/components/sales/FreeIssuePromotionSuggestions.tsx

@@ -1,4 +1,4 @@
-"use client"
+"use client"
 
 import Link from "next/link"
 import { Lightbulb, PackageCheck } from "lucide-react"
@@ -11,7 +11,7 @@ export function FreeIssuePromotionSuggestions({ suggestion }: { suggestion: Sale
   if (!suggestion || suggestion.lines.length === 0) {
     return (
       <div className="rounded-2xl border border-dashed p-6 text-sm text-muted-foreground">
-        No free-issue promotion suggestions were generated for this slip yet.
+        No free-issue suggestions were generated for this slip yet.
       </div>
     )
   }
@@ -22,10 +22,10 @@ export function FreeIssuePromotionSuggestions({ suggestion }: { suggestion: Sale
         <div>
           <div className="inline-flex items-center gap-2 rounded-full bg-amber-500/10 px-3 py-1 text-xs font-semibold uppercase tracking-wide text-amber-700">
             <Lightbulb className="size-3.5" />
-            Backend suggestion
+            Suggestion only
           </div>
           <h2 className="mt-2 text-lg font-semibold text-foreground">Free-issue promotions</h2>
-          <p className="text-sm text-muted-foreground">The server suggests reward quantities and alternate products for this slip.</p>
+          <p className="text-sm text-muted-foreground">These are suggestions only. You can review them before creating a free issue.</p>
         </div>
         <Link href="/dashboard/sales/free-issues/new" className={cn(buttonVariants({ variant: "outline", size: "sm" }))}>
           Create free issue
@@ -40,14 +40,12 @@ export function FreeIssuePromotionSuggestions({ suggestion }: { suggestion: Sale
                 <div className="font-medium text-foreground">{line.itemName}</div>
                 <div className="text-sm text-muted-foreground">{line.itemSku} • Qty {line.qty}</div>
               </div>
-              <div className="rounded-full bg-primary/10 px-3 py-1 text-xs font-semibold text-primary">
-                Buy {line.triggerQty} get {line.suggestedFreeQty} free
-              </div>
+              <div className="rounded-full bg-primary/10 px-3 py-1 text-xs font-semibold text-primary">Free issue</div>
             </div>
 
             <div className="mt-3 flex flex-wrap gap-2 text-sm">
               {line.rewardOptions.map((option, index) => (
-                <span key={option.itemId} className={cn("inline-flex items-center gap-1 rounded-full border px-3 py-1", index === 0 && "border-primary bg-primary/5 text-primary") }>
+                <span key={option.itemId} className={cn("inline-flex items-center gap-1 rounded-full border px-3 py-1", index === 0 && "border-primary bg-primary/5 text-primary")}>
                   {index === 0 ? <PackageCheck className="size-3.5" /> : null}
                   {option.name}
                 </span>
@@ -55,11 +53,11 @@ export function FreeIssuePromotionSuggestions({ suggestion }: { suggestion: Sale
             </div>
 
             <div className="mt-3 text-sm text-muted-foreground">
-              Suggested free qty: <span className="font-medium text-foreground">{line.suggestedFreeQty.toFixed(2)}</span>
+              Free qty: <span className="font-medium text-foreground">{line.suggestedFreeQty.toFixed(2)}</span>
             </div>
           </div>
         ))}
       </div>
     </div>
   )
-}
+}

Frontend/erp-system/hooks/use-allowed-uoms.ts

@@ -0,0 +1,73 @@
+"use client"
+
+// Per-item allowed-UOM lookup for document line forms.
+//
+// Every line on a document can reference a different item, so this caches by itemId and
+// fetches each one once. A naive refetch on every line edit would cost one request per line
+// on a 20-line invoice; the cache keeps it to one request per distinct item.
+import { useCallback, useEffect, useRef, useState } from "react"
+
+import { itemsApi } from "@/lib/api/items"
+import { AllowedUom } from "@/types/master-data"
+
+export interface AllowedUomLookup {
+  /** Allowed units for an item, or `undefined` while it is still loading / unknown. */
+  get: (itemId: number | null | undefined) => AllowedUom[] | undefined
+  /** Ensure an item's units are loaded. Safe to call repeatedly; in-flight requests are shared. */
+  load: (itemId: number | null | undefined) => void
+}
+
+export function useAllowedUoms(): AllowedUomLookup {
+  const [cache, setCache] = useState<Record<number, AllowedUom[]>>({})
+  // Tracks in-flight and failed ids so a repeated render never re-issues the same request.
+  const pending = useRef<Set<number>>(new Set())
+
+  const load = useCallback((itemId: number | null | undefined) => {
+    if (!itemId || pending.current.has(itemId)) return
+    pending.current.add(itemId)
+    itemsApi
+      .allowedUoms(itemId)
+      .then((uoms) => setCache((prev) => ({ ...prev, [itemId]: uoms })))
+      .catch(() => {
+        // Leave the id marked so we don't hammer a failing endpoint. The picker falls back
+        // to the global UOM list (see `pickerOptions`), and the server still rejects an
+        // invalid unit on save — this is a degraded experience, not a correctness hole.
+      })
+  }, [])
+
+  const get = useCallback(
+    (itemId: number | null | undefined) => (itemId ? cache[itemId] : undefined),
+    [cache],
+  )
+
+  return { get, load }
+}
+
+/**
+ * Single-item variant for screens with one item in scope (the conversion editor, a stock
+ * enquiry filtered to one item).
+ */
+export function useItemAllowedUoms(itemId: number | null | undefined): AllowedUom[] {
+  const [uoms, setUoms] = useState<AllowedUom[]>([])
+
+  useEffect(() => {
+    if (!itemId) {
+      setUoms([])
+      return
+    }
+    let cancelled = false
+    itemsApi
+      .allowedUoms(itemId)
+      .then((res) => {
+        if (!cancelled) setUoms(res)
+      })
+      .catch(() => {
+        if (!cancelled) setUoms([])
+      })
+    return () => {
+      cancelled = true
+    }
+  }, [itemId])
+
+  return uoms
+}

Frontend/erp-system/lib/api/general-ledger.ts

@@ -37,6 +37,11 @@ import {
   ReceivedFromType,
   CreateReceivedChequeRequest,
   UpdateReceivedChequeStatusRequest,
+  CHEQUE_BOOK_STATUS_BY_CODE,
+  CHEQUE_PAGE_ISSUE_STATUS_BY_CODE,
+  PAYEE_TYPE_BY_CODE,
+  RECEIVED_FROM_TYPE_BY_CODE,
+  RECEIVED_CHEQUE_STATUS_BY_CODE,
 } from "@/types/general-ledger"
 
 const GL_BASE = "/api/v1/gl"
@@ -257,50 +262,100 @@ export const cashAccountTypesApi = {
  * routes, not a numeric id. No `list()`/`get()` for pages standalone — a book's pages are always
  * read via `get(chequeBookNo, true)`'s `pages[]`, which is the only place this frontend needs them.
  */
+// GL sends `ChequeBook.status`/`ChequePage.issueStatus`/`ChequePage.payeeType`/
+// `ReceivedCheque.receivedFromType`/`ReceivedCheque.status` as raw integers, not their string
+// name (06_Enums_Reference.md — no global JsonStringEnumConverter on GL's side; see the long
+// comment above the `*_BY_CODE` maps in types/general-ledger.ts for why). These `Raw*` shapes
+// describe exactly what GL's JSON actually contains for those fields; the `map*` functions below
+// translate them into this frontend's normal string-enum `ChequeBook`/`ChequePage`/`ReceivedCheque`
+// types immediately after each call returns, so every other file in this app can keep comparing
+// against `ChequeBookStatus.Active` etc. exactly as before.
+type RawChequePage = Omit<ChequePage, "issueStatus" | "payeeType"> & {
+  issueStatus: number
+  payeeType: number | null
+}
+type RawChequeBook = Omit<ChequeBook, "status" | "pages"> & {
+  status: number
+  pages: RawChequePage[]
+}
+type RawReceivedCheque = Omit<ReceivedCheque, "receivedFromType" | "status"> & {
+  receivedFromType: number
+  status: number
+}
+
+function mapChequePage(raw: RawChequePage): ChequePage {
+  return {
+    ...raw,
+    issueStatus: CHEQUE_PAGE_ISSUE_STATUS_BY_CODE[raw.issueStatus],
+    payeeType: raw.payeeType == null ? null : PAYEE_TYPE_BY_CODE[raw.payeeType],
+  }
+}
+
+function mapChequeBook(raw: RawChequeBook): ChequeBook {
+  return {
+    ...raw,
+    status: CHEQUE_BOOK_STATUS_BY_CODE[raw.status],
+    pages: (raw.pages ?? []).map(mapChequePage),
+  }
+}
+
+function mapReceivedCheque(raw: RawReceivedCheque): ReceivedCheque {
+  return {
+    ...raw,
+    receivedFromType: RECEIVED_FROM_TYPE_BY_CODE[raw.receivedFromType],
+    status: RECEIVED_CHEQUE_STATUS_BY_CODE[raw.status],
+  }
+}
+
 export const chequeBooksApi = {
-  list(params?: {
+  async list(params?: {
     bankAccountId?: number
     branchId?: number
     status?: ChequeBookStatus
     page?: number
     pageSize?: number
   }): Promise<GlPagedResult<ChequeBook>> {
-    return glRequest<GlPagedResult<ChequeBook>>("/cheque-books", { query: { ...params } })
+    const res = await glRequest<GlPagedResult<RawChequeBook>>("/cheque-books", { query: { ...params } })
+    return { ...res, items: res.items.map(mapChequeBook) }
   },
 
   /** `expandPages` maps to GL's `?expand=pages` — omit it for just the book's own fields. */
-  get(chequeBookNo: string, expandPages = false): Promise<ChequeBook> {
-    return glRequest<ChequeBook>(`/cheque-books/${encodeURIComponent(chequeBookNo)}`, {
+  async get(chequeBookNo: string, expandPages = false): Promise<ChequeBook> {
+    const res = await glRequest<RawChequeBook>(`/cheque-books/${encodeURIComponent(chequeBookNo)}`, {
       query: expandPages ? { expand: "pages" } : undefined,
     })
+    return mapChequeBook(res)
   },
 
   /** Auto-generates every leaf (`totalLeaves` `ChequePage` rows, all `Unused`) in the same call — the response's `pages[]` already has them. */
-  create(request: CreateChequeBookRequest): Promise<ChequeBook> {
-    return glRequest<ChequeBook>("/cheque-books", { method: "POST", body: request })
+  async create(request: CreateChequeBookRequest): Promise<ChequeBook> {
+    const res = await glRequest<RawChequeBook>("/cheque-books", { method: "POST", body: request })
+    return mapChequeBook(res)
   },
 }
 
 export const chequePagesApi = {
-  issue(chequeNo: string, request: IssueChequePageRequest): Promise<ChequePage> {
-    return glRequest<ChequePage>(`/cheque-pages/${encodeURIComponent(chequeNo)}/issue`, {
+  async issue(chequeNo: string, request: IssueChequePageRequest): Promise<ChequePage> {
+    const res = await glRequest<RawChequePage>(`/cheque-pages/${encodeURIComponent(chequeNo)}/issue`, {
       method: "PUT",
       body: request,
     })
+    return mapChequePage(res)
   },
 
   /** `Clear`/`Bounce`/`Cancel`/`Void` — only valid from certain `issueStatus` values, see `types/general-ledger.ts`'s `ChequePageStatusAction`. */
-  updateStatus(chequeNo: string, request: UpdateChequePageStatusRequest): Promise<ChequePage> {
-    return glRequest<ChequePage>(`/cheque-pages/${encodeURIComponent(chequeNo)}/status`, {
+  async updateStatus(chequeNo: string, request: UpdateChequePageStatusRequest): Promise<ChequePage> {
+    const res = await glRequest<RawChequePage>(`/cheque-pages/${encodeURIComponent(chequeNo)}/status`, {
       method: "PUT",
       body: request,
     })
+    return mapChequePage(res)
   },
 }
 
 /** Received Cheques — cheques received from customers/suppliers/others, deliberately unlinked to any `ChequeBook`. */
 export const receivedChequesApi = {
-  list(params?: {
+  async list(params?: {
     companyId?: number
     branchId?: number
     status?: ReceivedChequeStatus
@@ -308,15 +363,18 @@ export const receivedChequesApi = {
     page?: number
     pageSize?: number
   }): Promise<GlPagedResult<ReceivedCheque>> {
-    return glRequest<GlPagedResult<ReceivedCheque>>("/received-cheques", { query: { ...params } })
+    const res = await glRequest<GlPagedResult<RawReceivedCheque>>("/received-cheques", { query: { ...params } })
+    return { ...res, items: res.items.map(mapReceivedCheque) }
   },
 
-  create(request: CreateReceivedChequeRequest): Promise<ReceivedCheque> {
-    return glRequest<ReceivedCheque>("/received-cheques", { method: "POST", body: request })
+  async create(request: CreateReceivedChequeRequest): Promise<ReceivedCheque> {
+    const res = await glRequest<RawReceivedCheque>("/received-cheques", { method: "POST", body: request })
+    return mapReceivedCheque(res)
   },
 
   /** `Deposit`/`Clear`/`Return`/`Cancel` — only valid from certain statuses, see `types/general-ledger.ts`'s `ReceivedChequeStatusAction`. */
-  updateStatus(id: number, request: UpdateReceivedChequeStatusRequest): Promise<ReceivedCheque> {
-    return glRequest<ReceivedCheque>(`/received-cheques/${id}/status`, { method: "PUT", body: request })
+  async updateStatus(id: number, request: UpdateReceivedChequeStatusRequest): Promise<ReceivedCheque> {
+    const res = await glRequest<RawReceivedCheque>(`/received-cheques/${id}/status`, { method: "PUT", body: request })
+    return mapReceivedCheque(res)
   },
 }

Frontend/erp-system/lib/api/items.ts

@@ -3,6 +3,7 @@
 import { apiRequest, apiRequestWithETag, buildQuery } from "@/lib/api-client"
 import { ApiResult, EntityStatus, PagedResponse } from "@/types/common"
 import {
+  AllowedUom,
   CreateItemRequest,
   Item,
   ItemListItem,
@@ -60,10 +61,20 @@ export const itemsApi = {
     })
   },
 
+  /**
+   * Replace the item's conversions. Every row must be `<other> → baseUomId` with a factor
+   * greater than zero; the reverse direction, a self-conversion, or a row from the base UOM
+   * is rejected with 422 (the engine only ever looks up `<other> → base` and never inverts).
+   */
   updateUomConversions(itemId: number, request: UpdateUomConversionsRequest): Promise<UpdateUomConversionsResponse> {
     return apiRequest<UpdateUomConversionsResponse>(`/items/${itemId}/uom-conversions`, {
       method: "PUT",
       body: request,
     })
   },
+
+  /** The UOMs this item can be transacted in — base UOM first, then each conversion source. */
+  allowedUoms(itemId: number): Promise<AllowedUom[]> {
+    return apiRequest<AllowedUom[]>(`/items/${itemId}/uoms`)
+  },
 }

Frontend/erp-system/lib/uom.ts

@@ -0,0 +1,94 @@
+// The single place the UI resolves and renders units of measure.
+//
+// Before this module, ~10 screens each re-declared their own inline `uoms.find(...)` under
+// three different names, with two different unknown-UOM fallbacks (`#12` vs `UOM 12`), and
+// there was no quantity formatter anywhere. Everything unit-shaped goes through here now.
+//
+// The one rule these helpers encode: **conversion toward base is authoritative.** The server
+// stores stock, layers and the ledger exclusively in an item's base UOM, and resolves the
+// base quantity when a document line is saved. `toBase` below exists to *preview* that for
+// the user at entry time; it is never the source of what gets posted.
+import { AllowedUom, Uom } from "@/types/master-data"
+
+/** Shown when a uomId has no matching row — one fallback across the whole app. */
+const UNKNOWN_UOM = "—"
+
+/** Quantities are `decimal(18,4)` server-side; trailing zeros are noise in a table. */
+const QTY_FORMATTER = new Intl.NumberFormat("en-US", {
+  minimumFractionDigits: 0,
+  maximumFractionDigits: 4,
+})
+
+/** `12` -> "PCS". Accepts any list with `uomId`/`name`, so `Uom[]` and `AllowedUom[]` both work. */
+export function uomName(
+  uomId: number | null | undefined,
+  uoms: readonly { uomId: number; name: string }[],
+): string {
+  if (uomId === null || uomId === undefined || uomId === 0) return UNKNOWN_UOM
+  return uoms.find((u) => u.uomId === uomId)?.name ?? UNKNOWN_UOM
+}
+
+/** `1234.5` -> "1,234.5". Quantity-specific: unlike `formatAmount` it does not force 2dp. */
+export function formatQtyValue(qty: number | null | undefined): string {
+  if (qty === null || qty === undefined || Number.isNaN(qty)) return "—"
+  return QTY_FORMATTER.format(qty)
+}
+
+/**
+ * `(24, 12, uoms)` -> "24 PCS". The formatter every screen showing a quantity should use —
+ * a bare number leaves the user guessing which unit a figure is in.
+ */
+export function formatQty(
+  qty: number | null | undefined,
+  uomId: number | null | undefined,
+  uoms: readonly { uomId: number; name: string }[],
+): string {
+  const value = formatQtyValue(qty)
+  const unit = uomName(uomId, uoms)
+  return unit === UNKNOWN_UOM ? value : `${value} ${unit}`
+}
+
+/** Convenience for stock screens, whose DTOs carry `baseUomName` directly from the server. */
+export function formatQtyWithName(qty: number | null | undefined, uomName: string | null | undefined): string {
+  const value = formatQtyValue(qty)
+  return uomName ? `${value} ${uomName}` : value
+}
+
+/**
+ * Converts an entered quantity to the item's base UOM, matching the server's arithmetic
+ * (multiply by the factor, round to 4dp). Display only — the authoritative base quantity is
+ * the one the server resolves and snapshots when the line is saved.
+ */
+export function toBase(qty: number, factor: number): number {
+  if (!Number.isFinite(qty) || !Number.isFinite(factor)) return 0
+  return Math.round(qty * factor * 10_000) / 10_000
+}
+
+/**
+ * The hint rendered beside a quantity input: `"= 24 PCS"` when the chosen unit is not the
+ * item's base, and `null` when it is (a "= 24 PCS" next to "24 PCS" is just noise).
+ *
+ * Making the conversion visible at entry is the point — previously a user only discovered a
+ * unit mismatch as a 422 when they tried to post the finished document.
+ */
+export function basePreview(
+  qty: number | null | undefined,
+  uomId: number | null | undefined,
+  allowed: readonly AllowedUom[],
+): string | null {
+  if (!qty || !uomId) return null
+  const selected = allowed.find((u) => u.uomId === uomId)
+  const base = allowed.find((u) => u.isBase)
+  if (!selected || !base || selected.isBase) return null
+  return `= ${formatQtyValue(toBase(qty, selected.factor))} ${base.name}`
+}
+
+/**
+ * Falls back to the global UOM list while an item's allowed units are still loading (or when
+ * no item is chosen yet), so a picker never renders empty. Once `allowed` arrives it wins —
+ * that narrowing is the whole reason the endpoint exists.
+ */
+export function pickerOptions(allowed: readonly AllowedUom[] | undefined, all: readonly Uom[]): { uomId: number; name: string }[] {
+  if (allowed && allowed.length > 0) return allowed.map((u) => ({ uomId: u.uomId, name: u.name }))
+  return all.map((u) => ({ uomId: u.uomId, name: u.name }))
+}

Frontend/erp-system/types/general-ledger.ts

@@ -410,6 +410,59 @@ export enum ReceivedChequeStatusAction {
   Cancel = "Cancel",
 }
 
+/**
+ * Confirmed (`06_Enums_Reference.md`, user-supplied) — GL has **no global `JsonStringEnumConverter`**
+ * registered. That's documented there as a request-body binding gotcha (a JSON-body enum field must
+ * be sent as its string name, parsed server-side via `Enum.TryParse`), but the same missing converter
+ * also governs the other direction: every one of these five fields is a real enum-typed property on
+ * GL's own response DTO (backed by an `integer` DB column, per that doc's "Persisted enums" table),
+ * so with no converter registered, GL's JSON response serializes each one as its **raw integer**
+ * (`1`/`2`/`3`/...), not the name — confirmed live by the user ("most status has integer numbers").
+ * Request bodies/query-string filters are unaffected and still take the string name as before (a
+ * JSON-body enum field is independently declared `string` server-side, and query-string enum
+ * binding parses names natively) — only inbound response values need translating. These maps do
+ * that translation, keyed by the exact integer values `06_Enums_Reference.md` documents; applied in
+ * `lib/api/general-ledger.ts` immediately after each GL call returns, so every consumer of
+ * `ChequeBook`/`ChequePage`/`ReceivedCheque` in this frontend keeps working with the same string
+ * enum values as before and never has to know GL sent a number.
+ */
+export const CHEQUE_BOOK_STATUS_BY_CODE: Record<number, ChequeBookStatus> = {
+  1: ChequeBookStatus.Active,
+  2: ChequeBookStatus.Completed,
+  3: ChequeBookStatus.Cancelled,
+}
+
+export const CHEQUE_PAGE_ISSUE_STATUS_BY_CODE: Record<number, ChequePageIssueStatus> = {
+  1: ChequePageIssueStatus.Unused,
+  2: ChequePageIssueStatus.Issued,
+  3: ChequePageIssueStatus.Cleared,
+  4: ChequePageIssueStatus.Bounced,
+  5: ChequePageIssueStatus.Cancelled,
+  6: ChequePageIssueStatus.Void,
+}
+
+/** `ChequePage.payeeType` is nullable — only set once a page is issued (`06_Enums_Reference.md`). */
+export const PAYEE_TYPE_BY_CODE: Record<number, PayeeType> = {
+  1: PayeeType.Supplier,
+  2: PayeeType.Customer,
+  3: PayeeType.Employee,
+  4: PayeeType.Other,
+}
+
+export const RECEIVED_FROM_TYPE_BY_CODE: Record<number, ReceivedFromType> = {
+  1: ReceivedFromType.Customer,
+  2: ReceivedFromType.Supplier,
+  3: ReceivedFromType.Other,
+}
+
+export const RECEIVED_CHEQUE_STATUS_BY_CODE: Record<number, ReceivedChequeStatus> = {
+  1: ReceivedChequeStatus.Received,
+  2: ReceivedChequeStatus.Deposited,
+  3: ReceivedChequeStatus.Cleared,
+  4: ReceivedChequeStatus.Returned,
+  5: ReceivedChequeStatus.Cancelled,
+}
+
 /**
  * A single leaf of a Cheque Book. GL's own reference confirms every field named in the `issue`
  * request body plus `issueStatus`/`printedAt`/`clearedDate`/`clearedByBank`/`cancelReason` in

Frontend/erp-system/types/master-data.ts

@@ -33,6 +33,11 @@ export interface ItemReorderSetting {
   reorderQty: number
 }
 
+/**
+ * A per-item conversion row. Always directional: `fromUom → toUom`, where `toUom` is
+ * required by the server to be the item's `baseUomId`. Quantity in `fromUom` × `factor`
+ * = quantity in base UOM. Saving one in the opposite direction is rejected with 422.
+ */
 export interface UomConversion {
   conversionId: number
   fromUom: number
@@ -40,6 +45,20 @@ export interface UomConversion {
   factor: number
 }
 
+/**
+ * A UOM an item may actually be transacted in — from `GET /items/{itemId}/uoms`.
+ *
+ * Line forms must populate their UOM picker from this rather than the global `uoms` list:
+ * choosing a unit the item has no conversion for is rejected when the line is saved.
+ */
+export interface AllowedUom {
+  uomId: number
+  name: string
+  /** Multiply a quantity in this UOM by `factor` to get the item's base UOM. 1 for the base itself. */
+  factor: number
+  isBase: boolean
+}
+
 /**
  * Full Item resource (docs/11 §2.1 `GET /items/{itemId}`).
  *

Frontend/erp-system/types/procurement.ts

@@ -138,11 +138,23 @@ export interface PoLine {
   itemId: number
   uomId: number
   warehouseId: number
+  /** Ordered quantity, in `uomId`. */
   qty: number
   unitPrice: number
   /** Rate, 0..1 (e.g. 0.18), not an amount. */
   tax: number
+  /**
+   * Received to date, in `uomId`. **Display only** — the server derives it by dividing
+   * `qtyReceivedBase` by `conversionFactor`, so it can drift. Use the base pair below for
+   * any remaining/outstanding/closed logic.
+   */
   qtyReceived: number
+  /** Ordered quantity in the item's base UOM — what over-receipt and PO closure compare on. */
+  qtyBase: number
+  /** Received to date in the item's base UOM. Authoritative. */
+  qtyReceivedBase: number
+  /** Factor used to derive the base pair from `uomId`; 1 when the line is in base UOM. */
+  conversionFactor: number
 }
 
 export interface PoTotals {

Frontend/erp-system/types/stock.ts

@@ -19,6 +19,9 @@ export interface OnHand {
   /** Always 0 in Phase 1 (sales reservation stub, FR-STK-11). */
   reserved: number
   asOf: string
+  /** The item's base UOM — every quantity above is in it. For labelling, not conversion. */
+  baseUomId: number
+  baseUomName: string
 }
 
 // --- 5.2 Ledger -------------------------------------------------------------------
@@ -41,6 +44,9 @@ export interface LedgerEntry {
   sourceDocId: number
   userId: number
   createdAt: string
+  /** The item's base UOM — `qtyBase` and `runningBalance` are in it. */
+  baseUomId: number
+  baseUomName: string
 }
 
 // --- 5.3 Valuation ------------------------------------------------------------------

Testing/e2e/.env.e2e.example

@@ -0,0 +1,14 @@
+# Copy to .env.e2e and fill in real values. Never commit .env.e2e.
+
+# Frontend origin the browser navigates to (Next.js proxies /api/v1/* server-side from here).
+E2E_BASE_URL=http://localhost:3000
+
+# Backend origin, used only to build absolute API paths in error messages / docs; all
+# actual requests go through E2E_BASE_URL's same-origin /api/v1 proxy.
+E2E_API_URL=http://localhost:5224
+
+# Credentials for a real AuthHex-backed user with access to Receiving, Production, and
+# Stock modules. AuthHex is an external identity provider (see docs/11-BACKEND-PHASE1.md
+# §2.0) - there is no local seed for this account, it must already exist upstream.
+E2E_ADMIN_EMAIL=e2e-tester@example.com
+E2E_ADMIN_PASSWORD=change-me

Testing/e2e/README.md

@@ -0,0 +1,155 @@
+# ERP-Core E2E tests (Playwright)
+
+End-to-end tests for the three phases requested first: **GRN (receiving)**, **Production
+runs**, and **Stock movement** (transfers + adjustments), plus one chained scenario that
+walks all three in sequence. Sales and Accounts are intentionally out of scope for now.
+
+## Why Playwright, not Selenium
+
+The frontend is Next.js 16 / React 19. Playwright auto-waits for React state updates,
+ships trace/video capture on failure, and can drive the backend API directly (used here to
+seed test data), which made it a better fit than Selenium for this stack.
+
+## Prerequisites
+
+1. Backend running locally: `cd Backend/ERPCore && dotnet ef database update && dotnet run`
+   (needs `ASPNETCORE_ENVIRONMENT=Development` set — see the repo's local-env notes — and a
+   reachable Postgres instance). Defaults to `http://localhost:5224`.
+2. Frontend running locally: `cd Frontend/erp-system && npm install && npm run dev`.
+   Defaults to `http://localhost:3000` and proxies `/api/v1/*` to the backend same-origin.
+3. A real login for the tests. **Auth is fronted by an external AuthHex identity provider**
+   (`Backend/ERPCore/Controllers/AuthController.cs`) — there is no local seed for a user
+   account, so `E2E_ADMIN_EMAIL`/`E2E_ADMIN_PASSWORD` must be a real, already-provisioned
+   account with access to Receiving, Production, and Stock.
+4. A fresh-ish database is fine: `DataSeeder` (`Backend/ERPCore/Infra/Persistence/DataSeeder.cs`)
+   seeds the `MAIN`/`SHOP` warehouses, `PCS`/`BOX` UOMs, and a `General Goods` category that
+   these tests rely on existing. Everything else (vendors, items, purchase orders, a
+   production template) is created fresh per run by `support/api.ts` with unique
+   timestamp-suffixed codes, so reruns never collide with previous data.
+5. **`E2E_BASE_URL` must use `http://localhost`, not `127.0.0.1` or a LAN IP.** The session
+   cookie is written with `Secure = true` unconditionally
+   (`Backend/ERPCore/Infra/Auth/AuthCookieWriter.cs`); Chromium only treats plain-HTTP
+   `localhost` as a secure-enough origin to accept and resend a `Secure` cookie, so anything
+   else silently drops the session and every post-login request 401s.
+
+## Setup
+
+```bash
+cd Testing/e2e
+npm install
+npx playwright install --with-deps chromium
+cp .env.e2e.example .env.e2e   # then fill in E2E_ADMIN_EMAIL / E2E_ADMIN_PASSWORD
+```
+
+## Running
+
+```bash
+npm run test:e2e          # headless, all specs
+npm run test:e2e:ui       # interactive UI mode — best for first-run locator debugging
+npm run test:e2e:headed   # headed browser
+npm run report             # open the last HTML report
+```
+
+The `setup` project (`specs/global.setup.ts`) logs in once through the real `/login` form
+— the session is an httpOnly cookie, so there's no token to inject — and saves it to
+`.auth/admin.json`. Every other spec's `chromium` project reuses that storage state, so
+individual specs don't re-authenticate. `auth.spec.ts` is the exception: it explicitly runs
+with no stored session so it can exercise the login form itself.
+
+## Layout
+
+```
+Testing/e2e/
+├── playwright.config.ts
+├── support/
+│   ├── env.ts        # reads .env.e2e, resolves the storageState path
+│   └── api.ts        # ApiSeeder — creates vendors/items/POs/templates, reads stock on-hand
+├── pages/             # Page Object Models (one file per module)
+└── specs/
+    ├── global.setup.ts
+    ├── auth.spec.ts
+    ├── grn.spec.ts
+    ├── production.spec.ts
+    ├── stock-transfers.spec.ts
+    ├── stock-adjustments.spec.ts
+    └── chained-flow.spec.ts   # GRN -> Production -> Stock Transfer, one continuous scenario
+```
+
+## Coverage vs. what's deferred
+
+18 tests across auth, GRN, production runs, stock transfers/adjustments, and one chained
+flow. Deliberately deferred (all would need a second, multi-stage production template or
+custom-field scaffolding to exercise, which felt like scope creep for a first pass):
+
+- **Approve & transfer** on a non-terminal stage, and transferring a held-back remainder
+  from an `Approved` stage — both only apply to a multi-stage graph; the seeded template is
+  single-stage (entry == terminal) so every run here only ever exercises "Approve & receive".
+- **Reject intake** (pulling back delivered upstream WIP) — same reason, needs a
+  parent→child edge.
+- Client-side validation edges inside `StageDrawer`: completing a stage with produced qty
+  over the staged input, or a scrap qty with no scrap reason selected.
+- Adjustment reason-code → ledger-entry tagging spot-check (`GET /stock/ledger`) — the
+  positive/negative adjustment tests verify on-hand moves correctly but don't inspect the
+  ledger rows themselves.
+
+**Long-run item-dropdown ceiling.** The GRN/Transfer/Adjustment "new" pages load items via
+`itemsApi.list({ pageSize: 200 })` (a fixed page, not paginated further in the UI). Every
+spec run mints 2-3 new permanent items through `ApiSeeder.createItem`, and nothing deletes
+them. Once a dev database accumulates more than 200 active items, freshly-seeded items stop
+appearing in the Item combobox (and if the list sorts ascending by id, it's exactly the
+newest ones that fall off) — locators like `getByRole("option", { name: item.name })` will
+time out with no visible cause. If that starts happening, the fix is to seed one stable
+per-module item once and reuse it across runs instead of minting a fresh one each time
+(every assertion here is already delta-based, so that's a drop-in change).
+
+## Known limitation: a real, reproducible hydration bug
+
+Every load of the GRN/Production/Stock pages throws a genuine React hydration error
+("Minified React error #418" — text content mismatch between server and client render).
+It is **not intermittent** — it fires on every navigation — but its effect is: hydration
+recovery blanks the placeholder text of a random subset of that page's Select triggers for
+the rest of that page's life, while leaving the sibling `<Label>`/`<FieldLabel>` and the
+trigger's `role="combobox"` attribute intact. A `getByRole("combobox", { name: ... })`
+lookup is therefore unreliable on these pages; `support/ui.ts`'s `comboboxByLabel()` works
+around it by finding the trigger via its stable sibling label + role alone, never its
+(possibly-blanked) accessible name. The same file's `retryClick`/`clickToReveal`/
+`clickToRevealWithReload`/`submitAndWait` cover two related, separately-confirmed issues:
+short-lived disabled/not-yet-mounted trigger buttons (`RunActions.tsx`'s "Cancel run"/
+"Return leftover", gated on `run.status`), and stage/document actions whose UI only
+reflects an async POST once the response lands — reading stock through the API immediately
+after a click can otherwise race the backend commit. This is worth a look on the product
+side (root-causing the actual SSR/CSR mismatch would remove the workaround entirely), but
+was out of scope for a first E2E pass.
+
+**Backend also can't take concurrent Playwright workers yet.** Reference-data GETs
+(`/warehouses`, etc.) intermittently 500 when 2+ workers hit a plain `dotnet run` +
+local Postgres backend at once — confirmed by re-running the exact same suite at
+`workers: 1` with zero failures. `playwright.config.ts` pins `workers: 1` for that reason;
+raise it only against a backend that can actually take concurrent load.
+
+## Known limitation: no `data-testid`s yet
+
+None of the GRN/Production/Stock Transfer/Stock Adjustment components in
+`Frontend/erp-system` currently expose `data-testid` attributes, and several form controls
+have no accessible name at all (the Qty/Unit cost/Disc%/VAT% `<Input type="number">` cells
+in the GRN and Transfer line tables aren't wrapped in a `<label>` or given `aria-label`).
+Locators in `pages/` work around this with role/placeholder matching where an accessible
+name exists, and row + column-position locators (`row.locator('input[type="number"]').nth(n)`)
+where it doesn't — every such case is called out in a comment at the top of the relevant
+`pages/*.ts` file, along with the couple of same-text button pairs (e.g. "Cancel run" is
+both the trigger and the dialog's confirm label) that needed `.first()`/`.last()` to
+disambiguate. If a component's copy or layout changes, run `npm run test:e2e:ui` to see
+exactly which locator broke and fix it in `pages/*.ts` — the specs themselves shouldn't need
+to change.
+
+**Recommended fast-follow** (not done here, since it's a product-code change rather than a
+test-authoring one): add `data-testid` to the Select triggers, the Qty/cost inputs, and the
+line-table rows in the receiving/production/stock components. That would let every locator
+above swap from role/position matching to exact `data-testid` matching in one pass.
+
+## CI
+
+Not wired up yet — no GitHub Actions workflow exists in this repo. Once these specs are
+green locally, add `.github/workflows/e2e.yml` (spin up Postgres + backend + frontend as
+services, run `npm run test:e2e`, upload `playwright-report/` as an artifact) as a
+follow-up.

Testing/e2e/package-lock.json

@@ -0,0 +1,125 @@
+{
+  "name": "erp-core-e2e",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "erp-core-e2e",
+      "version": "1.0.0",
+      "devDependencies": {
+        "@playwright/test": "^1.49.0",
+        "@types/node": "^20.0.0",
+        "dotenv": "^16.4.5",
+        "typescript": "^5.4.0"
+      }
+    },
+    "node_modules/@playwright/test": {
+      "version": "1.62.1",
+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.62.1.tgz",
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+      "license": "MIT",
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+      }
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+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    },
+    "node_modules/undici-types": {
+      "version": "6.21.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.21.0.tgz",
+      "integrity": "sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==",
+      "dev": true,
+      "license": "MIT"
+    }
+  }
+}

Testing/e2e/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "erp-core-e2e",
+  "version": "1.0.0",
+  "private": true,
+  "description": "Playwright end-to-end tests for GRN, Production Runs, and Stock Movement flows.",
+  "scripts": {
+    "test:e2e": "playwright test",
+    "test:e2e:ui": "playwright test --ui",
+    "test:e2e:headed": "playwright test --headed",
+    "test:e2e:debug": "playwright test --debug",
+    "report": "playwright show-report"
+  },
+  "devDependencies": {
+    "@playwright/test": "^1.49.0",
+    "@types/node": "^20.0.0",
+    "dotenv": "^16.4.5",
+    "typescript": "^5.4.0"
+  }
+}

Testing/e2e/pages/GrnPages.ts

@@ -0,0 +1,120 @@
+import { Page, expect } from "@playwright/test"
+import { clickToReveal, selectOption, comboboxByLabel } from "../support/ui"
+
+// Locators verified against Frontend/erp-system/app/dashboard/receiving/grn/new/page.tsx
+// and .../grn/[id]/page.tsx. Things that DOM inspection caught and a placeholder-only guess
+// would not have:
+//   - The Qty/Unit cost/Disc%/VAT% <Input type="number"> cells carry no accessible name
+//     (no htmlFor/aria-label) - located by column position within the row instead.
+//   - On a PO-based line (line.poLineId set) Item/UOM render as plain text, not a Select -
+//     fillFirstLine() only touches the item combobox when one is actually present (checked by
+//     role alone, not name - see below).
+//   - Every page here intermittently throws a real React hydration error (#418) that blanks a
+//     random subset of Select triggers' placeholder text for that page's lifetime, WITHOUT
+//     affecting their sibling <Label> or role="combobox" attribute (support/ui.ts has the full
+//     writeup). So triggers are located via comboboxByLabel() (label + role, no name lookup)
+//     instead of getByRole("combobox", { name }) - the row-scoped item/uom/bin combos have no
+//     adjacent label and are instead found by position, which is equally immune to the bug.
+export class GrnNewPage {
+  constructor(private readonly page: Page) {}
+
+  async goto() {
+    await this.page.goto("/dashboard/receiving/grn/new")
+  }
+
+  async useDirectReceipt() {
+    await clickToReveal(
+      this.page.getByRole("button", { name: /direct receipt/i }),
+      comboboxByLabel(this.page, "Vendor")
+    )
+  }
+
+  async useAgainstPo() {
+    await clickToReveal(
+      this.page.getByRole("button", { name: /against po/i }),
+      comboboxByLabel(this.page, "Purchase order")
+    )
+  }
+
+  async selectVendor(name: string) {
+    await selectOption(this.page, comboboxByLabel(this.page, "Vendor"), name)
+  }
+
+  async selectWarehouse(name: string) {
+    await selectOption(this.page, comboboxByLabel(this.page, "Warehouse"), name)
+  }
+
+  /** `docNo` is what the PO option renders (`{docNo} — Vendor #{vendorId} ({status})`) - not the numeric id. */
+  async selectPurchaseOrder(docNo: string) {
+    await selectOption(this.page, comboboxByLabel(this.page, "Purchase order"), new RegExp(docNo))
+  }
+
+  private firstRow() {
+    return this.page.locator("table tbody tr").first()
+  }
+
+  /**
+   * Item and UOM are each only a combobox when the row is NOT tied to a PO line
+   * (`line.poLineId` gates both cells identically in the source - a PO line renders them as
+   * plain text instead). Checked per-cell (td:nth(0) for Item, td:nth(1) for UOM) rather than
+   * "row has any combobox", since the Bin/Hold-status cells always have one regardless of PO
+   * mode - a row-wide check would false-positive on a PO line and select the wrong control.
+   * Selecting the app doesn't auto-fill UOM from the chosen item, so a direct-receipt/off-PO
+   * line needs it set explicitly or submit blocks with "Select a UOM".
+   */
+  async fillFirstLine(opts: { item?: string; uom?: string; qty: number; unitCost?: number }) {
+    const row = this.firstRow()
+    const cells = row.locator("td")
+    if (opts.item) {
+      const itemCombo = cells.nth(0).getByRole("combobox")
+      if (await itemCombo.count()) {
+        await selectOption(this.page, itemCombo, opts.item)
+      }
+    }
+    if (opts.uom) {
+      const uomCombo = cells.nth(1).getByRole("combobox")
+      if (await uomCombo.count()) {
+        await selectOption(this.page, uomCombo, opts.uom)
+      }
+    }
+    const numberInputs = row.locator('input[type="number"]')
+    await numberInputs.nth(0).fill(String(opts.qty)) // Qty
+    if (opts.unitCost !== undefined) {
+      await numberInputs.nth(1).fill(String(opts.unitCost)) // Unit cost
+    }
+  }
+
+  async submit() {
+    await this.page.getByRole("button", { name: /create grn/i }).click()
+  }
+}
+
+export class GrnDetailPage {
+  constructor(private readonly page: Page) {}
+
+  async gotoById(grnId: number) {
+    await this.page.goto(`/dashboard/receiving/grn/${grnId}`)
+  }
+
+  /** GrnStatusBadge/HoldStatusBadge render the raw status string verbatim - exact match avoids
+   *  matching prose like "Confirmed — stock layers created" in the post-confirm success panel. */
+  async expectStatus(status: "Draft" | "Confirmed") {
+    await expect(this.page.getByText(status, { exact: true })).toBeVisible()
+  }
+
+  async confirm() {
+    await this.page.getByRole("button", { name: /confirm grn/i }).click()
+  }
+
+  async releaseFirstOnHoldLine() {
+    await this.page.getByRole("button", { name: /^release$/i }).first().click()
+  }
+
+  async rejectFirstOnHoldLine() {
+    await this.page.getByRole("button", { name: /^reject$/i }).first().click()
+  }
+
+  async expectCreateReturnLink() {
+    await expect(this.page.getByRole("link", { name: /create return/i })).toBeVisible()
+  }
+}

Testing/e2e/pages/LoginPage.ts

@@ -0,0 +1,23 @@
+import { Page, expect } from "@playwright/test"
+
+export class LoginPage {
+  constructor(private readonly page: Page) {}
+
+  async goto() {
+    await this.page.goto("/login")
+  }
+
+  async login(email: string, password: string) {
+    await this.page.locator("#email").fill(email)
+    await this.page.locator("#password").fill(password)
+    await this.page.getByRole("button", { name: /sign in/i }).click()
+  }
+
+  async expectLoggedIn() {
+    await expect(this.page).toHaveURL(/\/dashboard/)
+  }
+
+  async expectError() {
+    await expect(this.page.getByRole("alert")).toBeVisible()
+  }
+}

Testing/e2e/pages/ProductionRunPages.ts

@@ -0,0 +1,135 @@
+import { Page, expect } from "@playwright/test"
+import { clickToReveal, clickToRevealWithReload, selectOption, comboboxByLabel, submitAndWait } from "../support/ui"
+
+// Locators verified against Frontend/erp-system/app/dashboard/production/runs/page.tsx,
+// .../runs/[id]/page.tsx, .../runs/[id]/StageDrawer.tsx, and .../runs/[id]/RunActions.tsx.
+// Key DOM facts that shaped these locators:
+//   - "Start Run" (the list page's dialog trigger, capital R) and "Start run" (the dialog's
+//     submit button, lowercase r) both match a case-insensitive /start run/i once the dialog
+//     is open (the trigger stays mounted behind it) - the submit click is scoped to
+//     getByRole("dialog") to avoid a strict-mode double match.
+//   - STAGE_STATUS_LABEL.InProgress is "In Progress" - the same text StageStatusLegend
+//     always renders on the run detail page, so a run-status assertion of "In Progress"
+//     collides with the legend. expectStatus() takes the first DOM match, which is always
+//     the run-header badge (it renders before the legend section).
+//   - AlertDialogContent's rejectForRework confirmation reuses "Reject for rework" as both
+//     the trigger and the confirm button's label - first()/last() disambiguates, same as
+//     cancelRun's "Cancel run" trigger/confirm pair.
+//   - Every page here intermittently throws a real React hydration error (#418) that blanks a
+//     random subset of Select triggers' placeholder text for that page's lifetime, without
+//     affecting their sibling <FieldLabel> or role="combobox" attribute (support/ui.ts has the
+//     full writeup). Triggers are located via comboboxByLabel() (label + role, no name lookup)
+//     instead of getByRole("combobox", { name }); the scrap-reason Select has no adjacent
+//     label, so it's found via its "Scrapped" sibling block instead.
+//   - Every stage/run action button here fires an async POST that the UI only reflects once the
+//     response lands (StageDrawer/RunActions' `submit()` wrapper) - submitAndWait() (support/ui.ts)
+//     waits for that specific response instead of just the click event, so a test reading stock
+//     right after clicking "Approve & receive" (etc.) doesn't race the backend commit.
+export class ProductionRunListPage {
+  constructor(private readonly page: Page) {}
+
+  async goto() {
+    await this.page.goto("/dashboard/production/runs")
+  }
+
+  async openStartRunDialog() {
+    await clickToReveal(
+      this.page.getByRole("button", { name: /start run/i }),
+      this.page.getByRole("dialog")
+    )
+  }
+
+  async startRun(opts: { template: string; targetQty: number; warehouse: string }) {
+    await this.openStartRunDialog()
+    const dialog = this.page.getByRole("dialog")
+    await selectOption(this.page, comboboxByLabel(dialog, "Template"), opts.template)
+    await dialog.locator("#target-qty").fill(String(opts.targetQty))
+    await selectOption(this.page, comboboxByLabel(dialog, "Warehouse"), opts.warehouse)
+    await submitAndWait(this.page, dialog.getByRole("button", { name: /^start run$/i }), "/production-runs")
+  }
+}
+
+export class ProductionRunDetailPage {
+  constructor(private readonly page: Page) {}
+
+  async gotoById(runId: number) {
+    await this.page.goto(`/dashboard/production/runs/${runId}`)
+  }
+
+  async expectStatus(status: RegExp | string) {
+    await expect(this.page.getByText(status).first()).toBeVisible()
+  }
+
+  /** Opens the StageDrawer for a named stage node on the React Flow canvas. */
+  async openStage(stageName: string) {
+    await clickToReveal(
+      this.page.getByText(stageName, { exact: true }),
+      this.page.getByRole("button", { name: /save quantities/i })
+    )
+  }
+
+  /** The StageDrawer is a modal Sheet - run-level actions (Return leftover, Cancel run) sit
+   *  behind it and need it dismissed first. */
+  async closeStageDrawer() {
+    await this.page.keyboard.press("Escape")
+  }
+
+  async saveQuantities() {
+    // updateStageQuantities is a PUT, unlike every other stage action.
+    await submitAndWait(this.page, this.page.getByRole("button", { name: /save quantities/i }), "/quantities", "PUT")
+  }
+
+  async startStage() {
+    await submitAndWait(this.page, this.page.getByRole("button", { name: /^start stage$/i }), "/start")
+  }
+
+  async completeStage(opts: { producedQty: number; scrappedQty?: number }) {
+    await this.page.getByRole("spinbutton", { name: /produced/i }).first().fill(String(opts.producedQty))
+    if (opts.scrappedQty) {
+      await this.page.getByRole("spinbutton", { name: /scrapped/i }).first().fill(String(opts.scrappedQty))
+      const scrapBlock = this.page.getByText("Scrapped", { exact: true }).locator("../..")
+      await selectOption(this.page, scrapBlock.getByRole("combobox"), /.+/)
+    }
+    await submitAndWait(this.page, this.page.getByRole("button", { name: /complete stage/i }), "/complete")
+  }
+
+  async approveAndReceive() {
+    await submitAndWait(this.page, this.page.getByRole("button", { name: /approve\s*&\s*receive/i }), "/approve")
+  }
+
+  async approveAndTransfer() {
+    await submitAndWait(this.page, this.page.getByRole("button", { name: /approve\s*&\s*transfer/i }), "/approve")
+  }
+
+  async rejectForRework() {
+    const button = this.page.getByRole("button", { name: /^reject for rework$/i })
+    await clickToReveal(button.first(), this.page.getByRole("dialog"))
+    await submitAndWait(this.page, button.last(), "/reject")
+  }
+
+  async openReturnLeftoverDialog() {
+    await clickToRevealWithReload(
+      this.page,
+      this.page.getByRole("button", { name: /return leftover/i }),
+      this.page.getByRole("dialog")
+    )
+  }
+
+  async returnLeftover(opts: { material: string; qty: number; reason: string }) {
+    await this.openReturnLeftoverDialog()
+    const dialog = this.page.getByRole("dialog")
+    await selectOption(this.page, comboboxByLabel(dialog, "Consumed material"), opts.material)
+    await dialog.locator("#return-qty").fill(String(opts.qty))
+    await selectOption(this.page, comboboxByLabel(dialog, "Reason"), opts.reason)
+    await submitAndWait(this.page, dialog.getByRole("button", { name: /return to stock/i }), "/return-leftover")
+  }
+
+  async cancelRun(opts: { reason: string; note?: string }) {
+    const cancelRunButton = this.page.getByRole("button", { name: /^cancel run$/i })
+    const dialog = this.page.getByRole("dialog")
+    await clickToRevealWithReload(this.page, cancelRunButton.first(), dialog)
+    await selectOption(this.page, comboboxByLabel(dialog, "Reason"), opts.reason)
+    if (opts.note) await dialog.locator("#cancel-note").fill(opts.note)
+    await submitAndWait(this.page, cancelRunButton.last(), "/cancel")
+  }
+}

Testing/e2e/pages/StockPages.ts

@@ -0,0 +1,82 @@
+import { Page, expect } from "@playwright/test"
+import { selectOption, comboboxByLabel } from "../support/ui"
+
+// Locators verified against Frontend/erp-system/app/dashboard/stock/transfers/new/page.tsx,
+// .../transfers/[id]/page.tsx, and .../stock/adjustments/new/page.tsx.
+// Every page here intermittently throws a real React hydration error (#418) that blanks a
+// random subset of Select triggers' placeholder text for that page's lifetime, without
+// affecting their sibling <Label> or role="combobox" attribute (support/ui.ts has the full
+// writeup). Triggers are located via comboboxByLabel() (label + role, no name lookup) instead
+// of getByRole("combobox", { name }); the row-scoped item combo has no adjacent label and is
+// instead found by position (it's the first combobox in the row).
+export class StockTransferNewPage {
+  constructor(private readonly page: Page) {}
+
+  async goto() {
+    await this.page.goto("/dashboard/stock/transfers/new")
+  }
+
+  async fill(opts: { fromWarehouse: string; toWarehouse: string; item: string; qty: number }) {
+    await selectOption(this.page, comboboxByLabel(this.page, "From warehouse"), opts.fromWarehouse)
+    await selectOption(this.page, comboboxByLabel(this.page, "To warehouse"), opts.toWarehouse)
+
+    const row = this.page.locator("table tbody tr").first()
+    await selectOption(this.page, row.getByRole("combobox").first(), opts.item)
+    // The Qty <Input type="number"> carries no accessible name - it's the only number input in the row.
+    await row.locator('input[type="number"]').fill(String(opts.qty))
+  }
+
+  async submit() {
+    await this.page.getByRole("button", { name: /create transfer/i }).click()
+  }
+}
+
+export class StockTransferDetailPage {
+  constructor(private readonly page: Page) {}
+
+  async gotoById(transferId: number) {
+    await this.page.goto(`/dashboard/stock/transfers/${transferId}`)
+  }
+
+  /**
+   * TransferStatusBadge renders the raw enum literal ("Draft" | "InTransit" | "Received") -
+   * exact match, since "Received" is also a substring of the post-receive success panel's
+   * heading ("Received — destination layers created").
+   */
+  async expectStatus(status: "Draft" | "InTransit" | "Received") {
+    await expect(this.page.getByText(status, { exact: true })).toBeVisible()
+  }
+
+  async dispatch() {
+    await this.page.getByRole("button", { name: /^dispatch$/i }).click()
+  }
+
+  async receive() {
+    await this.page.getByRole("button", { name: /^receive$/i }).click()
+  }
+}
+
+export class StockAdjustmentNewPage {
+  constructor(private readonly page: Page) {}
+
+  async goto() {
+    await this.page.goto("/dashboard/stock/adjustments/new")
+  }
+
+  async fill(opts: { warehouse: string; reasonCode: string; item: string; qtyDelta: number }) {
+    await selectOption(this.page, comboboxByLabel(this.page, "Warehouse"), opts.warehouse)
+    await selectOption(this.page, comboboxByLabel(this.page, "Reason code"), opts.reasonCode)
+
+    const row = this.page.locator("table tbody tr").first()
+    await selectOption(this.page, row.getByRole("combobox").first(), opts.item)
+    await row.getByPlaceholder(/e\.g\. -15 or 50/i).fill(String(opts.qtyDelta))
+  }
+
+  async submit() {
+    await this.page.getByRole("button", { name: /post adjustment/i }).click()
+  }
+
+  async expectPosted() {
+    await expect(this.page.getByRole("button", { name: /new adjustment/i })).toBeVisible()
+  }
+}

Testing/e2e/playwright.config.ts

@@ -0,0 +1,35 @@
+import { defineConfig, devices } from "@playwright/test"
+import { env, AUTH_STORAGE_STATE } from "./support/env"
+
+export default defineConfig({
+  testDir: "./specs",
+  fullyParallel: false, // specs share warehouse/item reference data via the ledger - keep runs serial per file
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 1 : 0,
+  // Multiple workers hit the local dev backend concurrently across spec files and it can't
+  // take it: confirmed reference-data GETs (e.g. /warehouses) intermittently 500 under 2+
+  // workers against a plain `dotnet run` + local Postgres, and pass every time at workers: 1.
+  // Bump this only against a backend that can actually take concurrent load (a real CI service
+  // container, not a single dev-mode process).
+  workers: 1,
+  reporter: [["html", { open: "never" }], ["list"]],
+  timeout: 45_000,
+  expect: { timeout: 10_000 },
+  use: {
+    baseURL: env.baseUrl,
+    trace: "on-first-retry",
+    screenshot: "only-on-failure",
+    video: "retain-on-failure",
+  },
+  projects: [
+    {
+      name: "setup",
+      testMatch: /global\.setup\.ts/,
+    },
+    {
+      name: "chromium",
+      use: { ...devices["Desktop Chrome"], storageState: AUTH_STORAGE_STATE },
+      dependencies: ["setup"],
+    },
+  ],
+})

Testing/e2e/specs/auth.spec.ts

@@ -0,0 +1,29 @@
+import { test, expect } from "@playwright/test"
+import { LoginPage } from "../pages/LoginPage"
+import { env } from "../support/env"
+
+// Runs unauthenticated - unlike every other spec, it must not use the "chromium" project's
+// saved storageState, since it is exercising the login form itself.
+test.use({ storageState: { cookies: [], origins: [] } })
+
+test.describe("Login", () => {
+  test("valid credentials redirect to the dashboard", async ({ page }) => {
+    const login = new LoginPage(page)
+    await login.goto()
+    await login.login(env.adminEmail, env.adminPassword)
+    await login.expectLoggedIn()
+  })
+
+  test("invalid password shows an inline error and stays on /login", async ({ page }) => {
+    const login = new LoginPage(page)
+    await login.goto()
+    await login.login(env.adminEmail, "definitely-not-the-password")
+    await login.expectError()
+    await expect(page).toHaveURL(/\/login/)
+  })
+
+  test("session-expired redirect shows the amber notice", async ({ page }) => {
+    await page.goto("/login?next=/dashboard/receiving/grn")
+    await expect(page.getByText(/session is missing or expired/i)).toBeVisible()
+  })
+})

Testing/e2e/specs/chained-flow.spec.ts

@@ -0,0 +1,112 @@
+import { test, expect, APIRequestContext } from "@playwright/test"
+import { ApiSeeder, newApiContext, Warehouse, Item, Uom, Vendor } from "../support/api"
+import { GrnNewPage, GrnDetailPage } from "../pages/GrnPages"
+import { ProductionRunListPage, ProductionRunDetailPage } from "../pages/ProductionRunPages"
+import { StockTransferNewPage, StockTransferDetailPage } from "../pages/StockPages"
+
+// Full cross-module lifecycle: GRN receipt -> Production consumes the received stock and
+// produces a finished good -> Stock Transfer moves the finished good to a second warehouse.
+// All four modules post to the same StockLayer/StockLedger tables (docs/10 C.9), so this is
+// the scenario most likely to catch a regression in one module's ledger posting breaking
+// another's downstream read - the thing the per-module suites (grn.spec.ts,
+// production.spec.ts, stock-transfers.spec.ts) can't see in isolation.
+test.describe("Chained flow: GRN -> Production -> Stock Transfer", () => {
+  let api: APIRequestContext
+  let seeder: ApiSeeder
+  let sourceWarehouse: Warehouse
+  let destWarehouse: Warehouse
+  let vendor: Vendor
+  let uom: Uom
+  let rawItem: Item
+  let finishedItem: Item
+  let templateName: string
+
+  test.beforeAll(async () => {
+    api = await newApiContext()
+    seeder = new ApiSeeder(api)
+    sourceWarehouse = await seeder.firstWarehouse()
+    destWarehouse = await seeder.secondWarehouse()
+    uom = await seeder.firstUom()
+    vendor = await seeder.createVendor("Chained Flow Vendor")
+    rawItem = await seeder.createItem({ namePrefix: "Chained Raw Material" })
+    finishedItem = await seeder.createItem({ namePrefix: "Chained Finished Good" })
+
+    const template = await seeder.createSingleStageTemplate({
+      rawItemId: rawItem.itemId,
+      finishedItemId: finishedItem.itemId,
+      uomId: uom.uomId,
+    })
+    templateName = template.name
+  })
+
+  test.afterAll(async () => {
+    await api.dispose()
+  })
+
+  test("receive raw material, run production, transfer the finished good", async ({ page }) => {
+    // --- 1. GRN: receive the raw material into the source warehouse -----------------
+    const grnNew = new GrnNewPage(page)
+    await grnNew.goto()
+    await grnNew.useDirectReceipt()
+    await grnNew.selectVendor(vendor.name)
+    await grnNew.selectWarehouse(sourceWarehouse.name)
+    await grnNew.fillFirstLine({ item: rawItem.name, uom: uom.name, qty: 100, unitCost: 20 })
+    await grnNew.submit()
+
+    await expect(page).toHaveURL(/\/dashboard\/receiving\/grn\/\d+/)
+    const grnDetail = new GrnDetailPage(page)
+    await grnDetail.expectStatus("Draft")
+    await grnDetail.confirm()
+    await grnDetail.expectStatus("Confirmed")
+
+    const rawAfterGrn = await seeder.stockOnHand(rawItem.itemId, sourceWarehouse.warehouseId)
+    expect(rawAfterGrn.onHand).toBeCloseTo(100, 4)
+
+    // --- 2. Production: consume the raw material, produce the finished good ---------
+    const runList = new ProductionRunListPage(page)
+    await runList.goto()
+    await runList.startRun({ template: templateName, targetQty: 20, warehouse: sourceWarehouse.name })
+
+    await expect(page).toHaveURL(/\/dashboard\/production\/runs\/\d+/)
+    const runDetail = new ProductionRunDetailPage(page)
+    await runDetail.expectStatus(/in progress/i)
+
+    await runDetail.openStage("Assemble")
+    await runDetail.saveQuantities()
+    await runDetail.startStage()
+
+    const rawAfterStart = await seeder.stockOnHand(rawItem.itemId, sourceWarehouse.warehouseId)
+    expect(rawAfterStart.onHand).toBeLessThan(rawAfterGrn.onHand)
+
+    await runDetail.completeStage({ producedQty: 20 })
+    await runDetail.approveAndReceive()
+
+    const finishedAfterRun = await seeder.stockOnHand(finishedItem.itemId, sourceWarehouse.warehouseId)
+    expect(finishedAfterRun.onHand).toBeCloseTo(20, 4)
+
+    // --- 3. Stock Transfer: move the finished good to a second warehouse ------------
+    const transferNew = new StockTransferNewPage(page)
+    await transferNew.goto()
+    await transferNew.fill({
+      fromWarehouse: sourceWarehouse.name,
+      toWarehouse: destWarehouse.name,
+      item: finishedItem.name,
+      qty: 20,
+    })
+    await transferNew.submit()
+
+    await expect(page).toHaveURL(/\/dashboard\/stock\/transfers\/\d+/)
+    const transferDetail = new StockTransferDetailPage(page)
+    await transferDetail.expectStatus("Draft")
+    await transferDetail.dispatch()
+    await transferDetail.expectStatus("InTransit")
+    await transferDetail.receive()
+    await transferDetail.expectStatus("Received")
+
+    // --- 4. Final assertions across the whole chain ----------------------------------
+    const finishedAtSource = await seeder.stockOnHand(finishedItem.itemId, sourceWarehouse.warehouseId)
+    const finishedAtDest = await seeder.stockOnHand(finishedItem.itemId, destWarehouse.warehouseId)
+    expect(finishedAtSource.onHand).toBeCloseTo(0, 4)
+    expect(finishedAtDest.onHand).toBeCloseTo(20, 4)
+  })
+})