feat: Implement fixed sale price functionality for items

- Added a toggle for fixed sale price vs stock value in the item creation form.
- Introduced validation to ensure all variants have a price greater than 0 when fixed price mode is selected.
- Updated the item model to include a nullable salePrice field, which is used for sales only and does not affect GRN/FIFO/ledger.
- Enhanced the GRN page to allow off-PO items and included a refresh button to update the item list without reloading the page.
- Updated documentation to reflect changes in item pricing and GRN handling.

Backend/ERPCore/Domain/Entities/Item.cs

@@ -33,6 +33,14 @@ public class Item
     public StockNature StockNature { get; set; }
     public TrackingMode TrackingMode { get; set; }
     public string? TaxClass { get; set; }
+
+    /// <summary>
+    /// Optional fixed selling price used by Sales only. <c>null</c> means "use stock value"
+    /// (the item is sold at its FIFO stock cost at sale time); a value is the fixed sale price.
+    /// Never enters costing/GRN/FIFO (docs/10 Part C.1, C.9).
+    /// </summary>
+    public decimal? SalePrice { get; set; }
+
     public EntityStatus Status { get; set; } = EntityStatus.Active;
 
     public DateTime CreatedAt { get; set; }

Backend/ERPCore/Dtos/Items/ItemDtos.cs

@@ -9,7 +9,7 @@ namespace ERPCore.Dtos.Items;
 public sealed record ItemListItemDto(
     int ItemId, string Sku, string Name, int CategoryId, int? SubCategoryId, int? BrandId,
     int BaseUomId, int? DefaultVendorId, StockNature StockNature, TrackingMode TrackingMode,
-    string? TaxClass, EntityStatus Status);
+    string? TaxClass, decimal? SalePrice, EntityStatus Status);
 
 /// <summary>A single per-warehouse reorder policy row.</summary>
 public sealed record ItemReorderDto(int WarehouseId, decimal ReorderPoint, decimal ReorderQty);
@@ -27,7 +27,7 @@ public sealed record ItemDetailDto(
     int ItemId, string Sku, string Name, string? Description, int CategoryId,
     int? SubCategoryId, int? BrandId, int BaseUomId, int? DefaultVendorId,
     StockNature StockNature, TrackingMode TrackingMode,
-    string? TaxClass, EntityStatus Status, IReadOnlyList<ItemReorderDto> Reorder,
+    string? TaxClass, decimal? SalePrice, EntityStatus Status, IReadOnlyList<ItemReorderDto> Reorder,
     IReadOnlyList<UomConversionDto> Conversions,
     DateTime CreatedAt, DateTime? UpdatedAt);
 
@@ -62,6 +62,8 @@ public sealed class CreateItemRequest
     [Required, EnumDataType(typeof(StockNature))] public StockNature StockNature { get; set; }
     [EnumDataType(typeof(TrackingMode))] public TrackingMode TrackingMode { get; set; } = TrackingMode.None;
     [StringLength(20)] public string? TaxClass { get; set; }
+    /// <summary>Optional fixed sale price (Sales only). Null ⇒ sell at stock/FIFO value.</summary>
+    [Range(0, double.MaxValue)] public decimal? SalePrice { get; set; }
 }
 
 public sealed class UpdateItemRequest
@@ -79,6 +81,8 @@ public sealed class UpdateItemRequest
     [Required, EnumDataType(typeof(StockNature))] public StockNature StockNature { get; set; }
     [EnumDataType(typeof(TrackingMode))] public TrackingMode TrackingMode { get; set; } = TrackingMode.None;
     [StringLength(20)] public string? TaxClass { get; set; }
+    /// <summary>Optional fixed sale price (Sales only). Null ⇒ sell at stock/FIFO value.</summary>
+    [Range(0, double.MaxValue)] public decimal? SalePrice { get; set; }
 }
 
 public sealed class UpdateItemStatusRequest

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

@@ -19,6 +19,9 @@ public sealed class ItemConfiguration : IEntityTypeConfiguration<Item>
         builder.Property(i => i.Description).HasMaxLength(1000);
         builder.Property(i => i.TaxClass).HasMaxLength(20);
 
+        // Sales-only fixed selling price; nullable (null ⇒ sell at stock/FIFO value).
+        builder.Property(i => i.SalePrice).HasPrecision(18, 4);
+
         builder.Property(i => i.StockNature)
             .HasConversion<string>().HasMaxLength(20).IsRequired();
         builder.Property(i => i.TrackingMode)

Backend/ERPCore/Infra/Persistence/Migrations/ErpDbContextModelSnapshot.cs

@@ -385,6 +385,10 @@ namespace ERPCore.Infra.Persistence.Migrations
                         .HasColumnType("xid")
                         .HasColumnName("xmin");
 
+                    b.Property<decimal?>("SalePrice")
+                        .HasPrecision(18, 4)
+                        .HasColumnType("numeric(18,4)");
+
                     b.Property<string>("Sku")
                         .IsRequired()
                         .HasMaxLength(50)

Backend/ERPCore/Services/ItemService.cs

@@ -79,7 +79,7 @@ public sealed class ItemService : IItemService
             .Select(i => new ItemListItemDto(
                 i.ItemId, i.Sku, i.Name, i.CategoryId, i.SubCategoryId, i.BrandId,
                 i.BaseUomId, i.DefaultVendorId,
-                i.StockNature, i.TrackingMode, i.TaxClass, i.Status))
+                i.StockNature, i.TrackingMode, i.TaxClass, i.SalePrice, i.Status))
             .ToListAsync(ct);
 
         return PagedResponse<ItemListItemDto>.Create(rows, query.Page, query.PageSize, total);
@@ -117,6 +117,7 @@ public sealed class ItemService : IItemService
             StockNature = request.StockNature,
             TrackingMode = request.TrackingMode,
             TaxClass = request.TaxClass,
+            SalePrice = request.SalePrice,
             Status = EntityStatus.Active,
             CreatedAt = DateTime.UtcNow
         };
@@ -158,6 +159,7 @@ public sealed class ItemService : IItemService
         item.StockNature = request.StockNature;
         item.TrackingMode = request.TrackingMode;
         item.TaxClass = request.TaxClass;
+        item.SalePrice = request.SalePrice;
         item.UpdatedAt = DateTime.UtcNow;
 
         await SaveGuardingConcurrencyAsync(ct);
@@ -348,7 +350,7 @@ public sealed class ItemService : IItemService
     private static ItemDetailDto ToDetail(Item i) => new(
         i.ItemId, i.Sku, i.Name, i.Description, i.CategoryId, i.SubCategoryId, i.BrandId,
         i.BaseUomId, i.DefaultVendorId,
-        i.StockNature, i.TrackingMode, i.TaxClass, i.Status,
+        i.StockNature, i.TrackingMode, i.TaxClass, i.SalePrice, i.Status,
         i.ReorderSettings
             .OrderBy(r => r.WarehouseId)
             .Select(r => new ItemReorderDto(r.WarehouseId, r.ReorderPoint, r.ReorderQty))

Backend/PROGRESS.md

@@ -27,6 +27,7 @@ Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit**
 - [x] Item Type master (FR-MD-10) — CRUD + status + ETag; **unreferenced by design**, feeds the builder dropdown only
 - [x] SubCategory (FR-MD-04) — nested list/create under a category, `PUT`/`PATCH status` by id; `Item.subCategoryId` nullable FK, validated to belong to `categoryId`
 - [x] Product Configuration (FR-MD-11) — singleton `GET`/`PUT /product-config`; `CONFIG_DISABLED` gating on item writes
+- [x] Item **sale price** (FR-MD-01, 2026-07-22) — nullable `Item.SalePrice` (`numeric(18,4)`); on all Item DTOs (list/detail/create/update), validated `>= 0`. **Sales-only** — never enters GRN/FIFO/ledger. `null` ⇒ sell at stock value. Migration `AddItemSalePrice`. See the 2026-07-22 Done entry.
 
 > ### 2026-07-16 — Brands, Subcategories, Item Types, Product Config (migration #2)
 > Makes real three concepts the frontend had been faking on mock data (`Frontend/erp-system/lib/api/mock-data.ts`), per docs/10 §B.3.1 FR-MD-09/10/11 and docs/11 §2.3/2.6/2.7/2.8.
@@ -75,6 +76,7 @@ Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit**
 ## 3. Goods Receipt
 > Implemented + **smoke test PASSED** 2026-07-13 (see §4 note for the shared stock verification). Same `[~]` reason as §1/§2: the §6 auth+audit gate.
 - [x] GRN create (against PO / direct), over-receipt tolerance — `unitCost` **defaults to the PO price but is now overridable per line** (variance recorded vs `poUnitPrice` snapshot — 02-SECURITY C.3 revised 2026-07-20; the old "client cost ignored" block is gone); direct receipt requires `vendorId` + entered cost (AR-04); over-receipt → `422 OVER_RECEIPT_TOLERANCE` (verified at open-qty boundary); batch created/reused per (item, batchNo). Serial capture deferred. **Discount/VAT added** — see the 2026-07-20 entry.
+- [x] **Off-PO lines on a PO-based GRN** (FR-GRN-01, 2026-07-22) — a line with `poLineId: null` on a PO-based GRN is received like a direct line (entered `unitCost`, no over-receipt check, PO balances untouched). **No code change was needed** — `GrnService.CreateAsync` already branches per-line on `input.PoLineId is not null`; documented + frontend-enabled. Same review/audit surface as AR-04 (02-SECURITY C.3).
 - [x] GRN confirm → FIFO layer + ledger + PO `qtyReceived` (single UoW txn) — verified: layers+ledger posted, running balance, PO → PartiallyReceived/FullyReceived, UOM→base conversion (10 Box-12 → 120 base @10). **Idempotent** re-confirm verified (no double-post). Note: `Idempotency-Key` accepted but idempotency is resource-state based (already-Confirmed replays existing result); a keyed idempotency store is deferred.
 - [x] Inspection hold release / reject — Release fully verified (OnHold excluded from `available`, then released). Reject removes on-hand + posts a reversing ledger entry; formal link to a Purchase Return is deferred (§3.4).
 
@@ -111,7 +113,11 @@ Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit**
 ## Done
 <!-- move [x] items here with date + note if the active list grows long -->
 
-### 2026-07-20 — PO draft lifecycle + GRN discount/VAT/price-override (migration `AddGrnPricingAndPoDraft`)
+### 2026-07-22 — Item fixed sale price + GRN off-PO items (migration `AddItemSalePrice`)
+- **Item sale price (FR-MD-01).** New nullable `Item.SalePrice` (`numeric(18,4)`, `ItemConfiguration.HasPrecision(18,4)`), threaded through `ItemListItemDto`/`ItemDetailDto`/`CreateItemRequest`/`UpdateItemRequest` (`[Range(0, …)]`) and mapped in `ItemService` (create/update/`ToDetail`/list projection). **Sales-only** — it never touches `GrnService`, FIFO, `StockLayer`, or the ledger, so receipt/costing behaviour is byte-for-byte unchanged. `null` ⇒ "use stock value"; the fixed-vs-stock choice is a frontend toggle, not a server field (no `price_mode` enum). docs/10 C.1/C.9 + decision #14, docs/11 §2.1, 02-SECURITY C.1.
+- **GRN off-PO items (FR-GRN-01).** A PO-based GRN may now carry lines with `poLineId: null` (item not on the PO). **No backend change** — `GrnService.CreateAsync` already routed such lines through the direct-receipt path (entered cost, no over-receipt check, no PO-balance update). Documented as intended behaviour; the frontend now exposes it. docs/10 FR-GRN-01/C.3 (`po_line_id` nullable) + decision #15, docs/11 §4.1, 02-SECURITY C.3.
+- **Migration** `AddItemSalePrice` — single nullable column add; no backfill (`Down()` drops it). **Applied** to the local DB (`dotnet ef database update` → Done).
+- **Verified:** `dotnet build` clean (compile succeeded; the only earlier failure was the running dev exe holding a file lock, resolved by stopping it). Migration Up applied. Frontend `tsc --noEmit` clean. End-to-end runtime smoke (Swagger/UI) still to be run by the user.
 - **PO draft lifecycle (FR-PROC-05 revised).** `CreatePurchaseOrderRequest.SaveAsDraft` (default `false` → auto-approve unchanged; `true` → `Draft`). New `POST /purchase-orders/{id}/submit` (Draft→Approved, else `409 PO_NOT_EDITABLE`) and `DELETE /purchase-orders/{id}` (Draft-only, else 409). `IsEditable` narrowed from "not FullyReceived/Closed/Cancelled" to **`Draft` only** — so `PUT` now 409s on any submitted PO. **Option B ("freely edit while open") is superseded**; docs/10 FR-PROC-05, docs/11 §3.3 updated. ⚠️ **Every pre-existing PO is `Approved` and therefore now uneditable/undeletable** — intended, not a regression. No schema change (reuses the existing `Draft` enum value).
 - **GRN discount + VAT + price override.** `GrnLine` gained `PoUnitPrice`(nullable snapshot), `DiscountPct`, `NetUnitCost`, `VatPct`, `VatAmount`, `LineTotal`. All derived figures **server-computed**, never client-supplied. FIFO layer + ledger now cost at **`NetUnitCost`** (after discount) — VAT is recoverable and never enters stock value (docs/10 FR-GRN-06 revised). For a PO line, `unitCost` defaults to the PO price but an entered override wins and a **variance** is recorded against `PoUnitPrice` (02-SECURITY C.3 revised — the "client cost ignored, decision locked" control is deliberately loosened; the variance trail + audit log are the compensating control). Multi-GRN-per-PO at differing prices (the 20/50/30 case) already worked via `openQty`/`QtyReceived` and is untouched.
 - **Migration** `AddGrnPricingAndPoDraft` — hand-added a data backfill (`UPDATE grn_lines SET NetUnitCost = UnitCost, LineTotal = ReceivedValue`) so existing GRN lines stay consistent with their already-posted FIFO layers; `PoUnitPrice` left NULL for historical rows (no retroactive variance). `Down()` drops the six columns cleanly.

Frontend/PROGRESS.md

@@ -27,7 +27,7 @@ Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit**
 - [~] Forgot password — change password screen — UI built (`app/login/forgot/reset`); not yet wired to API
 
 ## 2. Master Data screens
-- [~] Items (`app/dashboard/products` list + filters, `/new` create, `/[id]` full edit + ETag/If-Match with 412-conflict handling + activate/deactivate) — FR-MD-01/08. Reused the pre-existing "Products" sidebar entry/stub route rather than adding a new nav item. **2026-07-15, rebuilt twice this session — see the two same-day entries below for the full history; current state:** `/new` is now Category → Subcategory (always visible, disabled with "No subcategories" when the category has none) → Brand → a checkbox-driven **variant builder** sourced live from `variantCategoriesApi`, with no SKU/Name/Description/Default vendor/Tax class/Item type/Tracking mode/Base UOM fields left on the form at all (Item type/tracking mode/base UOM are now fixed constants — `"Stocked"`/`"None"`/`uomId 1` — baked into the submit call, not user-facing). Checking a category (Color, Size, or any custom one) reveals its value-entry UI; Color gets a native color picker + a required name field (stored internally as `"name|hex"`, decoded everywhere it's displayed/used for SKU) while every other category is free-text chips. A flat table (one column per checked category + SKU + Quantity) generalizes to any number of active categories via a cartesian-product `useMemo`, replacing the earlier hardcoded 2-column Color×Size matrix. Submitting loops `itemsApi.create()` once per combination; SKU is `<CategoryCode>-<value1Code>-<value2Code>...`; item name is `<Brand> <Category> - <value1>/<value2>...`. Added optional `brandId`/`initialQty` to `Item`/`CreateItemRequest`/`ItemListItem` (`types/master-data.ts`) — **deviation:** neither field is in the documented Item DTO (`docs/11-BACKEND-PHASE1.md` §2.1); `initialQty` is captured but not wired into the Stock Core ledger (informational only, no warehouse/GRN behind it).
+- [~] Items (`app/dashboard/products` list + filters, `/new` create, `/[id]` full edit + ETag/If-Match with 412-conflict handling + activate/deactivate) — FR-MD-01/08. **2026-07-22:** `/new` gained a **"Fixed price / Use stock value" sale-price toggle** — see the 2026-07-22 entry. Reused the pre-existing "Products" sidebar entry/stub route rather than adding a new nav item. **2026-07-15, rebuilt twice this session — see the two same-day entries below for the full history; current state:** `/new` is now Category → Subcategory (always visible, disabled with "No subcategories" when the category has none) → Brand → a checkbox-driven **variant builder** sourced live from `variantCategoriesApi`, with no SKU/Name/Description/Default vendor/Tax class/Item type/Tracking mode/Base UOM fields left on the form at all (Item type/tracking mode/base UOM are now fixed constants — `"Stocked"`/`"None"`/`uomId 1` — baked into the submit call, not user-facing). Checking a category (Color, Size, or any custom one) reveals its value-entry UI; Color gets a native color picker + a required name field (stored internally as `"name|hex"`, decoded everywhere it's displayed/used for SKU) while every other category is free-text chips. A flat table (one column per checked category + SKU + Quantity) generalizes to any number of active categories via a cartesian-product `useMemo`, replacing the earlier hardcoded 2-column Color×Size matrix. Submitting loops `itemsApi.create()` once per combination; SKU is `<CategoryCode>-<value1Code>-<value2Code>...`; item name is `<Brand> <Category> - <value1>/<value2>...`. Added optional `brandId`/`initialQty` to `Item`/`CreateItemRequest`/`ItemListItem` (`types/master-data.ts`) — **deviation:** neither field is in the documented Item DTO (`docs/11-BACKEND-PHASE1.md` §2.1); `initialQty` is captured but not wired into the Stock Core ledger (informational only, no warehouse/GRN behind it).
 - [~] UOM + conversions (`app/dashboard/products/uoms` flat list + create dialog; conversions edited inline on the Item detail page via `PUT /items/{itemId}/uom-conversions`) — FR-MD-02/03
 - [~] Categories (`app/dashboard/products/categories` indented tree view + create dialog with parent picker) — FR-MD-04. **2026-07-15:** added debounced search + Previous/Next pagination (`categoriesApi.list()` now takes `page`/`pageSize`/`q`/`sortOrder`, page size 5), matching the Vendor list's pagination pattern.
 - [~] Brands (`app/dashboard/products/brands` list + create/edit dialog + delete) — **not a documented FR/endpoint**; `lib/api/brands.ts` treats it as a standalone name-only master, same shape as Categories, since Item has no `brandId` in the doc. **2026-07-15:** added the same debounced search + pagination as Categories; `Item`/`CreateItemRequest`/`ItemListItem` gained `brandId` so the new-item variant builder (above) can attach a brand.
@@ -44,7 +44,7 @@ Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit**
 
 ## 4. Receiving screens
 - [~] GRN list (`app/dashboard/receiving/grn/page.tsx`) — loading/empty/error states, links to detail
-- [~] GRN create (`app/dashboard/receiving/grn/new/page.tsx`) — "Against PO" (picks an Approved/PartiallyReceived PO, prefills open lines) and "Direct receipt" (vendor + manual lines) modes; per-line bin, qty, unit cost, **discount % / VAT %** (with live after-discount/after-VAT line total + a per-row PO-price variance hint and a document total), hold status, and batch (batchNo+expiryDate) or serial-number-list capture driven by the item's `trackingMode`. **2026-07-20:** discount/VAT/variance added — see the 2026-07-20 entry.
+- [~] GRN create (`app/dashboard/receiving/grn/new/page.tsx`) — "Against PO" (picks an Approved/PartiallyReceived PO, prefills open lines) and "Direct receipt" (vendor + manual lines) modes; per-line bin, qty, unit cost, **discount % / VAT %** (with live after-discount/after-VAT line total + a per-row PO-price variance hint and a document total), hold status, and batch (batchNo+expiryDate) or serial-number-list capture driven by the item's `trackingMode`. **2026-07-20:** discount/VAT/variance added — see the 2026-07-20 entry. **2026-07-22:** "Add line" now works in **PO mode** (off-PO items) + **"New item"** (opens `/dashboard/products/new` in a new tab) + **refresh** icon — see the 2026-07-22 entry.
 - [~] GRN confirm (`app/dashboard/receiving/grn/[id]/page.tsx`) — renders returned `createdLayers`/`ledgerRefs`/`poStatus` as a confirmation panel (20-FRONTEND §4); sends a stable `Idempotency-Key` per detail-page session
 - [~] Inspection hold release / reject — Release/Reject buttons per on-hold line, shown once the GRN is `Confirmed`
 - Sidebar: added "Receiving" nav entry (`components/Layouts/AppSidebar.tsx`) → `/dashboard/receiving/grn`
@@ -90,6 +90,11 @@ Convention: `docs/01-DOC-GUIDE.md §6`. Update this file in the **same commit**
 ## Done
 <!-- move [x] items here with date + note if the active list grows long -->
 
+### 2026-07-22 — Item fixed sale price + GRN off-PO items / inline create
+- **Item sale-price toggle** (`app/dashboard/products/new/page.tsx`). New "Fixed price / Use stock value" segmented toggle (default **stock**). **Stock** sends `salePrice: null` on every created item. **Fixed** reveals a top "fix value" input that pre-fills a per-variant **Sale price** column (`priceFor(key) = pricesByKey[key] ?? fixValue`, so editing a row overrides only it while the rest follow the shared value); submit is blocked until **every** generated variant has a price `> 0` (`validateVariantPrices` in `lib/validations/master-data.ts`). Each variant's price rides its own `POST /items` in the existing non-transactional create loop. `types/master-data.ts`: `salePrice` added to `CreateItemRequest` (optional) and `Item`/`ItemListItem` (`number|null`).
+- **GRN off-PO items + inline create** (`app/dashboard/receiving/grn/new/page.tsx`). "Add line" is now shown in **both** PO and direct mode — an added PO-mode line has `poLineId: null` (editable item/UOM, `unitCost` required) and the server receives it as a direct line. New **"New item"** button opens `/dashboard/products/new` in a new browser tab (`window.open(..., "_blank", "noopener,noreferrer")` — the first new-tab pattern in the app), and a **refresh** icon (`refreshItems`) re-pulls `GET /items?status=Active` so the new item is selectable without reloading the in-progress GRN. Existing `validateLine` covers off-PO lines unchanged.
+- **Verified:** `tsc --noEmit` clean. Runtime browser verification (create fixed-priced variants; add an off-PO line + inline item on a PO GRN) is the next step.
+
 ### 2026-07-20 — PO draft lifecycle + GRN discount/VAT/price-override (backend + frontend, same pass)
 - **PO draft lifecycle.** `lib/api/purchase-orders.ts`: `isPoEditable` narrowed to `status === "Draft"` (was the three-status exclusion); added `submit(poId)` and `remove(poId)`. `types/procurement.ts`: `saveAsDraft?` on `CreatePurchaseOrderRequest`; `UpdatePurchaseOrderRequest` now `Omit`s it. `/new`: the single "Create PO" button split into **Save as draft** / **Create & submit**. `/[id]`: **Draft** shows the editable line grid + **Submit** + **Delete draft**; an issued-but-open PO (`Approved`/`PartiallyReceived`) is read-only with **Cancel PO** (with reason, disabled once receipts exist); closed/cancelled are terminal. The old Cancel button was gated on `isPoEditable` — that would have shown Cancel only for Draft, so the affordances were re-split into `editable` (Draft) vs `cancellable` (Approved/PartiallyReceived).
 - **GRN discount/VAT/variance.** `types/grn.ts`: `discountPct`/`vatPct` on `CreateGrnLineInput`; `poUnitPrice`/`discountPct`/`netUnitCost`/`vatPct`/`vatAmount`/`lineTotal`/`priceVariance` on `GrnLine`. `/new`: per-line Disc %/VAT % inputs, a client mirror of the server arithmetic (`computeLine`, display-only — server stays authoritative) driving a live Line total + document total, and a PO-price variance hint when the entered unit cost differs from the prefilled PO price. `/[id]`: renders the full cost breakdown (unit cost + variance, disc %, net cost, received value, VAT, line total) and a stock-value/VAT/document-total footer. `lib/validations/grn.ts`: 0–100 range checks on the two percentages.

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

@@ -13,7 +13,7 @@ import { productConfig } from "@/lib/api/product-config"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage } from "@/lib/error-map"
-import { validateVariantItemForm } from "@/lib/validations/master-data"
+import { validateVariantItemForm, validateVariantPrices } from "@/lib/validations/master-data"
 import { cn } from "@/lib/utils"
 import { Brand, Category, ItemType, ProductConfig, StockNature, SubCategory } from "@/types/master-data"
 
@@ -73,10 +73,21 @@ export default function NewItemPage() {
   // submit, without having to remove and re-add the whole value that produced it.
   const [removedVariantKeys, setRemovedVariantKeys] = useState<Set<string>>(new Set())
 
+  // Sales pricing (FR-MD-01). "stock" ⇒ salePrice sent as null (sell at FIFO value);
+  // "fixed" ⇒ every variant must carry a price. `fixValue` is the shared default that
+  // pre-fills rows; a per-key entry in `pricesByKey` overrides it for that one row only.
+  const [priceMode, setPriceMode] = useState<"stock" | "fixed">("stock")
+  const [fixValue, setFixValue] = useState<string>("")
+  const [pricesByKey, setPricesByKey] = useState<Record<string, string>>({})
+  const [priceErrors, setPriceErrors] = useState<Record<string, string>>({})
+
   const [errors, setErrors] = useState<Record<string, string>>({})
   const [submitError, setSubmitError] = useState<string | null>(null)
   const [submitting, setSubmitting] = useState(false)
 
+  // A row shows its own override if set, otherwise it follows the shared fix value.
+  const priceFor = (key: string) => pricesByKey[key] ?? fixValue
+
   useEffect(() => {
     Promise.all([
       categoriesApi.list({ pageSize: 200, status: "Active" }),
@@ -190,7 +201,11 @@ export default function NewItemPage() {
     setSubmitError(null)
     const nextErrors = validateVariantItemForm({ categoryId, hasVariants: variants.length > 0 })
     setErrors(nextErrors)
-    if (Object.keys(nextErrors).length > 0) return
+    // In fixed mode, block the whole submit until every variant has a price > 0.
+    const nextPriceErrors =
+      priceMode === "fixed" ? validateVariantPrices(variants.map((v) => v.key), priceFor) : {}
+    setPriceErrors(nextPriceErrors)
+    if (Object.keys(nextErrors).length > 0 || Object.keys(nextPriceErrors).length > 0) return
     if (baseUomId === null) {
       setSubmitError("No unit of measure exists yet — create one under Products → UOM before adding items.")
       return
@@ -212,6 +227,7 @@ export default function NewItemPage() {
           baseUomId,
           stockNature,
           trackingMode: "None",
+          salePrice: priceMode === "fixed" ? Number(priceFor(variant.key)) : null,
         })
         created += 1
       }
@@ -384,6 +400,59 @@ export default function NewItemPage() {
             </div>
           </div>
 
+          {/* Sales pricing (FR-MD-01). The toggle is frontend-only: "stock" sends
+              salePrice=null (sold at FIFO value); "fixed" requires a price per variant. */}
+          <div className="flex flex-col gap-4 rounded-xl border p-5">
+            <div>
+              <h2 className="text-lg font-semibold text-foreground">Sale price</h2>
+              <p className="text-sm text-muted-foreground">
+                Choose a fixed selling price, or leave it to the item&apos;s stock value.
+              </p>
+            </div>
+
+            <div className="inline-flex w-fit rounded-lg border p-1">
+              <button
+                type="button"
+                onClick={() => setPriceMode("stock")}
+                className={cn(
+                  "rounded-md px-4 py-2 text-base font-medium transition-colors",
+                  priceMode === "stock" ? "bg-primary text-primary-foreground" : "text-muted-foreground hover:bg-muted/50",
+                )}
+              >
+                Use stock value
+              </button>
+              <button
+                type="button"
+                onClick={() => setPriceMode("fixed")}
+                className={cn(
+                  "rounded-md px-4 py-2 text-base font-medium transition-colors",
+                  priceMode === "fixed" ? "bg-primary text-primary-foreground" : "text-muted-foreground hover:bg-muted/50",
+                )}
+              >
+                Fixed price
+              </button>
+            </div>
+
+            {priceMode === "fixed" && (
+              <div className="flex max-w-xs flex-col gap-2">
+                <Label className="text-base">Fix value (applies to all variants)</Label>
+                <Input
+                  type="number"
+                  min="0"
+                  step="0.01"
+                  inputMode="decimal"
+                  value={fixValue}
+                  onChange={(e) => setFixValue(e.target.value)}
+                  placeholder="0.00"
+                  className="h-11 text-base"
+                />
+                <p className="text-sm text-muted-foreground">
+                  Edit any row below to give that variant a different price.
+                </p>
+              </div>
+            )}
+          </div>
+
           {/* itemTypesEnabled is advisory — the server cannot enforce it (items hold no
               item-type reference), so this section IS the enforcement. */}
           {config?.itemTypesEnabled && (
@@ -469,6 +538,9 @@ export default function NewItemPage() {
                         <TableHead key={cat.itemTypeId} className="h-11 px-3 text-sm text-indigo-700">{cat.name}</TableHead>
                       ))}
                       <TableHead className="h-11 px-3 text-sm text-indigo-700">SKU</TableHead>
+                      {priceMode === "fixed" && (
+                        <TableHead className="h-11 px-3 text-sm text-indigo-700">Sale price</TableHead>
+                      )}
                       {/* Quantity column removed 2026-07-17: there is no `initialQty` on the
                           Item contract and no initial-receipt flow — stock arrives via a GRN.
                           The input was informational-only under the mock and would now be a
@@ -485,6 +557,31 @@ export default function NewItemPage() {
                           </TableCell>
                         ))}
                         <TableCell className="py-2.5 pr-1 pl-3 font-medium">{variant.sku}</TableCell>
+                        {priceMode === "fixed" && (
+                          <TableCell className="px-3 py-2.5">
+                            <Input
+                              type="number"
+                              min="0"
+                              step="0.01"
+                              inputMode="decimal"
+                              value={priceFor(variant.key)}
+                              onChange={(e) => {
+                                const value = e.target.value
+                                setPricesByKey((prev) => ({ ...prev, [variant.key]: value }))
+                                setPriceErrors((prev) => {
+                                  if (!prev[variant.key]) return prev
+                                  const next = { ...prev }
+                                  delete next[variant.key]
+                                  return next
+                                })
+                              }}
+                              placeholder="0.00"
+                              aria-invalid={!!priceErrors[variant.key]}
+                              className="h-10 w-28 text-base"
+                            />
+                            <FieldError errors={[priceErrors[variant.key] ? { message: priceErrors[variant.key] } : undefined]} />
+                          </TableCell>
+                        )}
                         <TableCell className="py-2.5 pr-3 pl-0">
                           <Button
                             type="button"

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

@@ -3,7 +3,7 @@
 import { useEffect, useState } from "react"
 import { useRouter } from "next/navigation"
 import Link from "next/link"
-import { ArrowLeft, Plus, Trash2 } from "lucide-react"
+import { ArrowLeft, ExternalLink, Plus, RefreshCw, Trash2 } from "lucide-react"
 
 import { grnsApi } from "@/lib/api/grns"
 import { purchaseOrdersApi } from "@/lib/api/purchase-orders"
@@ -107,6 +107,7 @@ export default function NewGrnPage() {
   const [lineErrors, setLineErrors] = useState<Record<string, Record<string, string>>>({})
   const [submitError, setSubmitError] = useState<string | null>(null)
   const [submitting, setSubmitting] = useState(false)
+  const [refreshingItems, setRefreshingItems] = useState(false)
 
   useEffect(() => {
     Promise.all([
@@ -188,6 +189,21 @@ export default function NewGrnPage() {
     }
   }
 
+  // Re-pull the active items list so an item created in the other tab (via "New item")
+  // becomes selectable without reloading the whole screen and losing the in-progress GRN.
+  async function refreshItems() {
+    setRefreshingItems(true)
+    try {
+      const res = await itemsApi.list({ pageSize: 200, status: "Active" })
+      setItems(res.items)
+      toast.success("Items refreshed", `${res.items.length} active item${res.items.length === 1 ? "" : "s"} loaded.`)
+    } catch (err) {
+      toast.error("Could not refresh items", errorMessage(err))
+    } finally {
+      setRefreshingItems(false)
+    }
+  }
+
   function updateLine(key: string, patch: Partial<DraftLine>) {
     setLines((prev) => prev.map((l) => (l.key === key ? { ...l, ...patch } : l)))
   }
@@ -384,14 +400,43 @@ export default function NewGrnPage() {
           )}
 
           <div className="flex flex-col gap-3">
-            <div className="flex items-center justify-between">
+            <div className="flex items-center justify-between gap-3">
-              <h2 className="text-base font-semibold text-foreground">Lines</h2>
+              <div>
-              {mode === "direct" && (
+                <h2 className="text-base font-semibold text-foreground">Lines</h2>
+                {mode === "po" && (
+                  <p className="text-sm text-muted-foreground">
+                    PO lines are prefilled. Use “Add line” to receive an item that isn’t on the PO.
+                  </p>
+                )}
+              </div>
+              <div className="flex items-center gap-2">
+                {/* Off-PO items are allowed on a PO-based GRN — the server treats a line with
+                    no poLineId as a direct receipt (docs/10 FR-GRN-01, revised). */}
                 <Button type="button" variant="outline" onClick={() => setLines((prev) => [...prev, emptyLine()])}>
                   <Plus className="size-5" />
                   Add line
                 </Button>
-              )}
+                {/* Create a brand-new item in a separate tab, then refresh to pick it up. */}
+                <Button
+                  type="button"
+                  variant="outline"
+                  onClick={() => window.open("/dashboard/products/new", "_blank", "noopener,noreferrer")}
+                >
+                  <ExternalLink className="size-5" />
+                  New item
+                </Button>
+                <Button
+                  type="button"
+                  variant="outline"
+                  size="icon"
+                  onClick={refreshItems}
+                  disabled={refreshingItems}
+                  aria-label="Refresh items"
+                  title="Refresh items"
+                >
+                  <RefreshCw className={cn("size-5", refreshingItems && "animate-spin")} />
+                </Button>
+              </div>
             </div>
 
             {poLoading && <Skeleton className="h-24 w-full" />}

Frontend/erp-system/lib/validations/master-data.ts

@@ -73,3 +73,23 @@ export function validateVariantItemForm(input: {
   if (!input.hasVariants) errors.variants = "Check at least one variant category and add its values"
   return errors
 }
+
+/**
+ * Fixed-price mode requires every generated variant to carry a sale price > 0
+ * (docs/20 §3.1). Returns a map keyed by variant key → message; empty when valid.
+ * In "stock" mode there is nothing to validate (prices are sent as null).
+ */
+export function validateVariantPrices(
+  variantKeys: string[],
+  priceFor: (key: string) => string,
+): Record<string, string> {
+  const errors: Record<string, string> = {}
+  for (const key of variantKeys) {
+    const raw = priceFor(key).trim()
+    const value = Number(raw)
+    if (raw === "" || Number.isNaN(value) || value <= 0) {
+      errors[key] = "Enter a price greater than 0"
+    }
+  }
+  return errors
+}

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

@@ -22,6 +22,8 @@ export interface ItemListItem {
   stockNature: StockNature
   trackingMode: TrackingMode
   taxClass: string | null
+  /** Fixed sale price (Sales only); null ⇒ sell at stock/FIFO value. */
+  salePrice: number | null
   status: EntityStatus
 }
 
@@ -59,6 +61,8 @@ export interface Item {
   stockNature: StockNature
   trackingMode: TrackingMode
   taxClass: string | null
+  /** Fixed sale price (Sales only); null ⇒ sell at stock/FIFO value. */
+  salePrice: number | null
   status: EntityStatus
   reorder: ItemReorderSetting[]
   conversions: UomConversion[]
@@ -81,6 +85,8 @@ export interface CreateItemRequest {
   stockNature: StockNature
   trackingMode: TrackingMode
   taxClass?: string | null
+  /** Optional fixed sale price (Sales only). Null/omitted ⇒ sell at stock/FIFO value. */
+  salePrice?: number | null
 }
 
 export type UpdateItemRequest = CreateItemRequest

docs/02-SECURITY.md

@@ -74,6 +74,7 @@ These are known, deliberately-accepted Phase-1 exposures. Each has a compensatin
 - [ ] Create/update DTOs exclude server-controlled fields (`status`, ids, timestamps)
 - [ ] Deactivate — not delete — referenced masters (FR-MD-08); hard delete blocked → `MASTER_IN_USE`
 - [ ] Nested/reference writes validate the target exists and is active
+- [ ] `Item.salePrice` is a **legitimately client-supplied** field (a deliberate exception to B.6's over-posting list) — validated `>= 0` server-side, nullable. It is **Sales-only** (never enters GRN/FIFO/ledger), so unlike GRN `unitCost` it has **no** inventory-value or costing impact; the fixed/stock-value choice is frontend UX (`docs/11 §2.1`).
 
 ### C.2 Procurement (Requisition / RFQ / PO / Purchase Return)
 - [ ] PO totals computed **server-side** from lines (never trust client totals)
@@ -86,7 +87,8 @@ These are known, deliberately-accepted Phase-1 exposures. Each has a compensatin
 - [ ] `unitCost` **defaults to the PO line price**; a per-line override **is now permitted** *(decision revised 2026-07-20 — was "locked, client cost ignored")*. When an override is entered it is used, and the PO price is snapshotted (`poUnitPrice`) so a **`priceVariance` is recorded** against it for review. Rationale: one PO legitimately spans batches received at different prices; the variance trail (plus the audit log) is the compensating control that replaces the old hard block.
 - [ ] **Derived figures stay server-computed** — `netUnitCost`/`receivedValue`/`vatAmount`/`lineTotal` are never accepted from the client, so the client cannot inflate stock value except by an *auditable* unit-cost override. Discount reduces inventory cost; **VAT is recoverable and never enters stock value**.
 - [ ] Direct GRN (no PO) remains the higher-scrutiny path where cost is entered with no PO to compare against → review flag + audit (**AR-04**)
-- [ ] Over-receipt tolerance enforced server-side → `OVER_RECEIPT_TOLERANCE`
+- [ ] **Off-PO lines on a PO-based GRN** (`poLineId: null`, 2026-07-22) are the **same exposure class as AR-04** — cost is entered with no PO line to compare against, and `OVER_RECEIPT_TOLERANCE` does not apply to them. Treat them with the direct-receipt scrutiny (review flag + audit); they do not touch PO balances.
+- [ ] Over-receipt tolerance enforced server-side → `OVER_RECEIPT_TOLERANCE` (PO-linked lines only; off-PO lines have no PO qty to check)
 - [ ] On-hold stock is not issuable (FR-WH-07); expired batch blocked
 
 ### C.4 Stock Core (FIFO / Ledger)

docs/10-BACKEND-PHASE1.md

@@ -118,7 +118,7 @@ One base currency; invoicing/3-way match in Accounting (GRN carries data); users
 ### B.3.1 Master Data (FR-MD)
 | ID | Requirement | Pri |
 |---|---|---|
-| FR-MD-01 | Maintain **Item master**: SKU (unique), name, description, category (+ optional subcategory), optional brand, **stock nature** (Stocked/NonStocked/Service), tracking mode (None/Batch/Serial), status, tax class, default vendor. | M |
+| FR-MD-01 | Maintain **Item master**: SKU (unique), name, description, category (+ optional subcategory), optional brand, **stock nature** (Stocked/NonStocked/Service), tracking mode (None/Batch/Serial), status, tax class, default vendor, **optional fixed sale price** (nullable; Sales-only — never enters costing/GRN/FIFO; `null` ⇒ item is sold at its stock/FIFO value). | M |
 | FR-MD-02 | Maintain **UOM master** with base UOM per item and **conversion factors** (purchase→stock→base). | M |
 | FR-MD-03 | Convert quantities between UOMs on every transaction; store base-UOM quantity in the ledger. | M |
 | FR-MD-04 | Maintain **item categories with one optional subcategory level**. An item references a category (required) and a subcategory (optional) that must belong to it. Deeper nesting is not supported. | S |
@@ -146,7 +146,7 @@ One base currency; invoicing/3-way match in Accounting (GRN carries data); users
 ### B.3.3 Goods Receipt (FR-GRN)
 | ID | Requirement | Pri |
 |---|---|---|
-| FR-GRN-01 | Create **GRN** against an approved PO, defaulting lines/quantities from open PO lines. | M |
+| FR-GRN-01 | Create **GRN** against an approved PO, defaulting lines/quantities from open PO lines. **Additional lines for items not on the PO are permitted** — a line with no `po_line_id` is received like a direct receipt (entered cost, no over-receipt check) and does not affect PO line balances. Off-PO lines are a review surface (see 02-SECURITY C.3). | M |
 | FR-GRN-02 | Support **GRN without PO** (direct/emergency) by permission, flagged for review. | S |
 | FR-GRN-03 | Support **over/under-receipt tolerances** (per item or global); warn or block beyond tolerance. | S |
 | FR-GRN-04 | Capture **batch + expiry** and/or **serial numbers** for tracked items on receipt. | M |
@@ -250,6 +250,8 @@ Adjustment: Damage, Theft/Loss, Count Variance, Expiry Write-off, System Correct
 | 11 | Category hierarchy depth | **Resolved:** dedicated `SUBCATEGORY` table, exactly two levels; `CATEGORY.parent_id` dropped. Item carries both FKs (subcategory nullable). Arbitrary nesting is not coming back. |
 | 12 | Item types / variants | **Resolved:** the `ItemType` **enum** was replaced by an **unreferenced master list**; Stocked/NonStocked/Service survives as `stock_nature`. Values are **SKU-encoded only** — no value table, no item link, no product-variation model (Part C.9 records the accepted trade-off). |
 | 13 | Product-config authorization | **Open:** `PUT /product-config` is gated by the door policy only, like every other endpoint. A `CONFIG_MANAGE` permission is reserved for when per-endpoint RBAC lands (decision #6). Until then any ERP-admitted user can flip the flags. |
+| 14 | Item sale price (fixed vs stock value) | **Resolved (2026-07-22):** a single **nullable** `ITEM.sale_price` — `NULL` ⇒ sell at stock/FIFO value, a value ⇒ fixed price. **Sales-only** (never touches GRN/FIFO/ledger). No `price_mode` enum; the create-time fixed/stock toggle is frontend UX that requires a price per generated variant when "fixed" is chosen (Part C.9). |
+| 15 | Off-PO lines on a PO-based GRN | **Resolved (2026-07-22):** allowed. `GRN_LINE.po_line_id` is nullable; a null line on a PO-based GRN is received like a direct receipt (entered cost, no over-receipt check) and does not touch PO balances. Same cost-entry/fraud surface as GRN-without-PO (AR-04) — flagged for review, not blocked (02-SECURITY C.3). |
 
 ---
 
@@ -267,7 +269,8 @@ UOM(uom_id PK, name)
 UOM_CONVERSION(conversion_id PK, item_id FK→ITEM, from_uom FK→UOM, to_uom FK→UOM, factor)
 ITEM(item_id PK, sku, name, category_id FK→CATEGORY, subcategory_id FK→SUBCATEGORY [nullable],
      brand_id FK→BRAND [nullable], base_uom_id FK→UOM,
-     default_vendor_id FK→VENDOR, stock_nature, tracking_mode, tax_class, status)
+     default_vendor_id FK→VENDOR, stock_nature, tracking_mode, tax_class,
+     sale_price [nullable], status)   -- sale_price: Sales-only selling price; NULL ⇒ sell at stock (FIFO) value
 ITEM_REORDER(reorder_id PK, item_id FK→ITEM, warehouse_id FK→WAREHOUSE, reorder_point, reorder_qty)
 VENDOR(vendor_id PK, code, name, terms, tax_reg, currency, status)
 WAREHOUSE(warehouse_id PK, code, name)
@@ -303,8 +306,9 @@ PURCHASE_RETURN_LINE(return_line_id PK, return_id FK→PURCHASE_RETURN,
 ```
 GRN(grn_id PK, doc_no, po_id FK→PURCHASE_ORDER, vendor_id FK→VENDOR,
      warehouse_id FK→WAREHOUSE, status, created_by FK→USER, created_at)
-GRN_LINE(grn_line_id PK, grn_id FK→GRN, po_line_id FK→PO_LINE, item_id FK→ITEM, uom_id FK→UOM,
+GRN_LINE(grn_line_id PK, grn_id FK→GRN, po_line_id FK→PO_LINE [nullable], item_id FK→ITEM, uom_id FK→UOM,
      bin_id FK→BIN, batch_id FK→BATCH, qty, unit_cost, received_value, hold_status)
+     -- po_line_id nullable: NULL for a direct receipt OR an off-PO line added to a PO-based GRN (FR-GRN-01)
 ```
 
 ## C.4 Batch / Serial
@@ -362,6 +366,7 @@ Note: `USER_ROLE` from the original placeholder sketch was dropped — a user ha
 ## C.9 Modeling notes (load-bearing)
 - **Item types are a dropdown, not a relationship.** `ITEM_TYPE` (Color, Size, Material) exists **only** to populate the frontend item-builder's dropdown via `GET /item-types`. Nothing references it and it references nothing — there is no value table and no join to `ITEM`. The builder cross-products the checked types into **one standalone item per combination**; the chosen values (Red, S, M) are encoded by the **client** into the generated SKU (`BL-0002` for one type, `BL-100-0003` for two) and the server only checks that SKU for uniqueness. **The item list is the record of what was built.** This is not a product-variation model: there is no parent-product entity and no variant hierarchy.
   - *Accepted trade-off (a decision, not an oversight):* the backend cannot answer "list all blue items", cannot filter or report by colour/size, and cannot validate that a SKU's segments correspond to real item types. Renaming an item type (`Color` → `Colour`) does **not** touch existing SKUs, which keep their old segments — the two are permanently decoupled the moment an item is created. If value-level querying is ever needed, an `ITEM_TYPE_VALUE` table plus a link table can be added additively, but existing SKUs will not be back-fillable without parsing them by hand.
+- **Sale price is a per-item scalar, not a variant/price table.** Because each "variant" is its own `ITEM` row (above), the optional selling price lives directly on `ITEM.sale_price` (nullable). `NULL` means "use stock value" — Sales values the item at its FIFO stock cost at sale time (FR-STK-04 / `STOCK_LAYER`); a value is a fixed selling price. It is **Sales-only**: it never participates in GRN, FIFO layering, or the stock ledger, so receipt/costing behaviour is identical whether the item is fixed-priced or not. The create-time "fixed price vs use stock value" choice is a **frontend UX toggle** — the contract is simply the nullable column, and the item builder requires a price on every generated variant when the user picks fixed pricing.
 - **Two-level categories.** `CATEGORY` no longer self-nests; `SUBCATEGORY` is the single optional level below it. An item stores both FKs rather than pointing only at the deepest node, so the parent is never inferred or lost. A subcategory cannot be reparented (it would silently invalidate the category of every item referencing it) — deactivate and recreate instead.
 - **Product config is a singleton, and only two of its flags are enforceable.** `subcategories_enabled` / `brands_enabled` gate item writes (`CONFIG_DISABLED`, 422). `item_types_enabled` is **advisory only** — since items carry no item-type reference, there is nothing on a write to reject; the frontend honours it by hiding the builder's type section. Reads are never gated, so existing data stays readable after a flag is switched off.
 - **FIFO = two structures.** `STOCK_LAYER` answers valuation ("what's on hand and at what cost"); `STOCK_LEDGER` answers history ("what moved, when, by whom"). Layers are keyed per item **per warehouse**.

docs/11-BACKEND-PHASE1.md

@@ -164,6 +164,8 @@ docs/10 C.9): every write below forwards to AuthHex's new `/api/role` functions
 
 ### 2.1 Items
 > **`itemType` → `stockNature` (2026-07-16).** The Stocked/NonStocked/Service field was renamed so the name `itemType` could be taken by the new Item Type master (§2.7) — an unrelated concept. Items gained `subCategoryId` and `brandId` (both nullable). Items carry **no** item-type reference: the values chosen in the builder are encoded into the client-generated SKU (docs/10 Part C.9).
+>
+> **`salePrice` added (nullable, 2026-07-22).** Every item body below carries `salePrice` (`number|null`). It is the **Sales-only** fixed selling price: `null` ⇒ the item is sold at its stock/FIFO value; a value ⇒ fixed price. It never affects GRN/FIFO/ledger. On write it is optional; when supplied it must be `>= 0` (else `400` validation). The item builder's "fixed price / use stock value" toggle is UI-only — the contract is just the nullable field.
 
 #### `GET /items`
 Query: `q`, `status` (`Active|Inactive`), `categoryId`, `subCategoryId`, `brandId`, `trackingMode` (`None|Batch|Serial`), + paging.
@@ -171,7 +173,8 @@ Query: `q`, `status` (`Active|Inactive`), `categoryId`, `subCategoryId`, `brandI
 ```json
 { "items": [ { "itemId": 1001, "sku": "ITM-1001", "name": "Steel Bolt M8x40",
       "categoryId": 12, "subCategoryId": 30, "brandId": 2, "baseUomId": 1, "defaultVendorId": 5,
-      "stockNature": "Stocked", "trackingMode": "Batch", "taxClass": "STD", "status": "Active" } ],
+      "stockNature": "Stocked", "trackingMode": "Batch", "taxClass": "STD",
+      "salePrice": 12.5000, "status": "Active" } ],
   "pagination": { "page": 1, "pageSize": 20, "totalItems": 1, "totalPages": 1 } }
 ```
 
@@ -181,7 +184,8 @@ Query: `q`, `status` (`Active|Inactive`), `categoryId`, `subCategoryId`, `brandI
   "description": "Grade 8.8 zinc-plated hex bolt", "categoryId": 12, "subCategoryId": 30,
   "brandId": 2, "baseUomId": 1,
   "defaultVendorId": 5, "stockNature": "Stocked", "trackingMode": "Batch", "taxClass": "STD",
-  "status": "Active", "reorder": [ { "warehouseId": 1, "reorderPoint": 500, "reorderQty": 2000 } ],
+  "salePrice": 12.5000, "status": "Active",
+  "reorder": [ { "warehouseId": 1, "reorderPoint": 500, "reorderQty": 2000 } ],
   "conversions": [ { "conversionId": 33, "fromUom": 7, "toUom": 1, "factor": 12 } ],
   "createdAt": "2026-06-01T08:00:00Z", "updatedAt": "2026-07-01T10:15:00Z" }
 ```
@@ -192,14 +196,14 @@ The `sku` is **generated by the client** (it encodes the chosen item-type values
 ```json
 { "sku": "ITM-1002", "name": "Steel Nut M8", "description": "Grade 8 zinc-plated hex nut",
   "categoryId": 12, "subCategoryId": 30, "brandId": 2, "baseUomId": 1, "defaultVendorId": 5,
-  "stockNature": "Stocked", "trackingMode": "None", "taxClass": "STD" }
+  "stockNature": "Stocked", "trackingMode": "None", "taxClass": "STD", "salePrice": 3.2500 }
 ```
 **201 Created** — `Location: /api/v1/items/1002`
 ```json
 { "itemId": 1002, "sku": "ITM-1002", "name": "Steel Nut M8", "categoryId": 12,
   "subCategoryId": 30, "brandId": 2, "baseUomId": 1,
   "defaultVendorId": 5, "stockNature": "Stocked", "trackingMode": "None", "taxClass": "STD",
-  "status": "Active", "createdAt": "2026-07-07T09:30:00Z" }
+  "salePrice": 3.2500, "status": "Active", "createdAt": "2026-07-07T09:30:00Z" }
 ```
 `400` → `code: SKU_DUPLICATE` if SKU exists.
 `422` → `code: CONFIG_DISABLED` if `subCategoryId` is sent while subcategories are disabled, or `brandId` while brands are disabled (§2.8).
@@ -530,11 +534,18 @@ Against a PO (lines default from open PO lines) or direct (`poId: null`, by perm
 { "poId": 342, "warehouseId": 1,
   "lines": [ { "poLineId": 900, "itemId": 1001, "uomId": 1, "binId": 45, "qty": 5000,
       "unitCost": 12.50, "discountPct": 10, "vatPct": 18, "holdStatus": "OnHold",
-      "batch": { "batchNo": "B-2607", "expiryDate": "2028-07-01" } } ] }
+      "batch": { "batchNo": "B-2607", "expiryDate": "2028-07-01" } },
+    { "poLineId": null, "itemId": 1050, "uomId": 1, "qty": 20,
+      "unitCost": 8.00, "holdStatus": "Available" } ] }
 ```
 `discountPct`/`vatPct` optional (default 0, range 0–100). `unitCost` on a **PO line** is an optional
 override: 0/omitted uses the PO price; a value wins and a variance is recorded (02-SECURITY C.3, revised).
 On a direct receipt `unitCost` is required.
+**Off-PO lines (`poLineId: null`) are allowed even on a PO-based GRN** (2026-07-22, FR-GRN-01) — the second
+line above receives an item that is not on the PO. Such a line behaves exactly like a direct-receipt line:
+`unitCost` is required, `OVER_RECEIPT_TOLERANCE` does **not** apply (there is no PO qty to check), and no PO
+line balance is touched. The inline "create new item" UI simply calls `POST /items` (§2.1) first, then adds
+the returned item as an off-PO line.
 **201 Created** — status `Draft`. All derived figures are **server-computed**:
 `netUnitCost = unitCost × (1 − discountPct/100)`, `receivedValue = qty × netUnitCost` (after discount,
 **before** VAT — this is the stock value), `vatAmount = receivedValue × vatPct/100`,

docs/20-FRONTEND.md

@@ -143,9 +143,11 @@ Vendors, Items, Categories, Subcategories, UOM, Warehouses, Brands, and Item Typ
 - **SKU generation stays client-side** (`buildVariantSku`) and is the *only* record of which colour/size an item is; the server only uniqueness-checks it. **Nothing can query items by colour** — accepted (`docs/10 Part C.9`).
 - **`remove()` → `updateStatus(id, "Inactive")`** everywhere. There are no `DELETE` endpoints on any master (FR-MD-08); the lists show a Status column and Deactivate/Activate.
 - **`initialQty` is gone** from the builder — the Item contract has no such field and there is no initial-receipt flow. Stock arrives via a GRN.
+- **Sale-price toggle on the builder (2026-07-22).** A "Fixed price / Use stock value" toggle sits on `/dashboard/products/new`. **Use stock value** (default) sends `salePrice: null` on every created item (sold at FIFO value). **Fixed price** reveals a top "fix value" input that pre-fills a per-variant `Sale price` column; each row is editable, and submit is blocked until **every** generated variant has a price `> 0`. The toggle is **frontend-only** — the contract is just the nullable `salePrice` field (`docs/11 §2.1`); it is Sales-only and never affects GRN/costing. The non-transactional create loop still applies — each variant's `salePrice` rides its own `POST /items`.
 - **Product Configuration** (`app/dashboard/products/settings`, `GET`/`PUT /product-config`) — only **3** of the original design's ~13 toggles exist. `subcategoriesEnabled`/`brandsEnabled` are server-enforced (`CONFIG_DISABLED`); **`itemTypesEnabled` is advisory** and this app is what honours it (it hides the builder's type section). The UI states that distinction on the screen rather than implying a guarantee.
 - **Non-transactional create loop:** the builder's per-row `itemsApi.create()` has no transaction — a `SKU_DUPLICATE` on row 7 of 12 leaves 6 items created. The error message now says how many landed rather than implying nothing happened. A transactional bulk-create endpoint would be the real fix.
 - **GRN edit/delete removed** — the API has no `PUT`/`DELETE` for a GRN; receipts are corrected by reversing documents (FR-X-05).
+- **GRN off-PO items + inline item create (2026-07-22).** On `/dashboard/receiving/grn/new`, "Add line" is available in **both** PO and direct mode — an added line in PO mode has `poLineId: null` and receives an item not on the PO (editable item/UOM dropdowns, `unitCost` required). A **"New item"** button opens `/dashboard/products/new` in a **new browser tab** (`window.open`, the first such pattern in the app), and a **refresh icon** re-pulls `GET /items?status=Active` so the newly created item is selectable **without** reloading the screen and losing the in-progress GRN. Server treats off-PO lines as direct receipts (no over-receipt check) — `docs/11 §4.1`.
 - **RFQ invited-vendors is not persisted** — `POST /rfqs` validates `vendorIds` then discards them, so the list/detail screens show quotations received instead of vendors invited.
 - **Known gap — serial numbers:** FR-GRN-04 requires capturing serials on receipt, but `CreateGrnLineInput` has no such field (only `batch`). The UI does not collect them rather than silently discarding them. Needs a backend change to honour the requirement.
 
@@ -159,7 +161,7 @@ Vendors, Items, Categories, Subcategories, UOM, Warehouses, Brands, and Item Typ
 **Client-side (UX only — safe to check locally):** purely input-level facts the browser already has.
 - Required fields present.
 - Format: SKU pattern, numeric fields numeric, date format, positive integers.
-- Range/bounds: `qty > 0`, `unitPrice >= 0`, `factor > 0`.
+- Range/bounds: `qty > 0`, `unitPrice >= 0`, `factor > 0`. Item `salePrice` is a client-supplied number — the builder requires `> 0` per variant in fixed mode; the server only checks `>= 0` on a supplied value (`docs/11 §2.1`).
 - Simple cross-field input rules: transfer `destWarehouseId != srcWarehouseId`.
 - Enum membership via constrained dropdowns (`stockNature` — ex-`itemType`, `trackingMode`, `countType`, `holdStatus`). Note the **Item Type** dropdown is *not* in this category: it's server data (`GET /item-types`), not an enum.