sku and item fix

Backend/ERPCore/Domain/Entities/ItemType.cs

@@ -7,12 +7,15 @@ namespace ERPCore.Domain.Entities;
 /// Material.
 /// <para>
 /// <b>Deliberately unlinked.</b> Nothing references this entity and it references
-/// nothing: there is no value table and no join to <see cref="Item"/>. Its only job is
-/// to feed the frontend's item-builder dropdown via <c>GET /item-types</c>. The chosen
+/// nothing: there is no value table and no join to <see cref="Item"/>. The chosen
 /// values (Red, S, M) are encoded by the client into the generated SKU
 /// (e.g. <c>BL-100-0003</c>) and are never stored or parsed server-side — the item list
 /// is the record of what was built. See the accepted trade-off in docs/10 Part C.9.
 /// </para>
+/// <para>
+/// It does, however, carry one piece of meaning the client acts on:
+/// <see cref="IsMeasurable"/>. So this is no longer purely a dropdown source.
+/// </para>
 /// Not to be confused with <see cref="Enums.StockNature"/> (Stocked/NonStocked/Service),
 /// which is what the old <c>ItemType</c> enum became.
 /// Model: docs/10-BACKEND-PHASE1.md Part C.1.
@@ -21,6 +24,24 @@ public class ItemType
 {
     public int ItemTypeId { get; set; }
     public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// When true, this dimension's values are content <b>measurements</b> (500 ml, 1 L) rather
+    /// than plain labels (Red, S). The item builder then captures a number + unit per value and
+    /// stamps that pair onto each generated item's <see cref="Item.ContentQty"/> /
+    /// <see cref="Item.ContentUnit"/>, instead of copying one form-level pair into every variant
+    /// — which is what makes "Coca-Cola in 500 ml / 1 L / 250 ml" three correctly sized items.
+    /// <para>
+    /// This is what lets an apparel <c>Size</c> (S/M/L) stay plain text while a
+    /// <c>Pack Size</c>/<c>Volume</c> dimension carries ml/g/L/kg.
+    /// </para>
+    /// <para>
+    /// A client hint only: the server never reads it when writing an item. Each item's pair is
+    /// still validated and normalised on its own by <c>ItemContent</c>.
+    /// </para>
+    /// </summary>
+    public bool IsMeasurable { get; set; }
+
     public EntityStatus Status { get; set; } = EntityStatus.Active;
 
     public DateTime CreatedAt { get; set; }

Backend/ERPCore/Dtos/ItemTypes/ItemTypeDtos.cs

@@ -5,12 +5,16 @@ namespace ERPCore.Dtos.ItemTypes;
 
 /// <summary>
 /// Item type resource (docs/11-BACKEND-PHASE1.md §2.7) — a dimension name such as Color
-/// or Size. Carries no values and no item linkage: <c>GET /item-types</c> exists to
-/// populate the frontend builder's dropdown, and the chosen values are encoded into the
+/// or Size. Carries no values and no item linkage: the chosen values are encoded into the
 /// client-generated SKU rather than stored (docs/10 Part C.9).
+/// <para>
+/// <c>IsMeasurable</c> marks a dimension whose values are content measurements (500 ml, 1 L)
+/// rather than plain labels; the builder captures a number + unit per value and writes it to
+/// each generated item's content size.
+/// </para>
 /// </summary>
 public sealed record ItemTypeDto(
-    int ItemTypeId, string Name, EntityStatus Status, DateTime CreatedAt, DateTime? UpdatedAt);
+    int ItemTypeId, string Name, bool IsMeasurable, EntityStatus Status, DateTime CreatedAt, DateTime? UpdatedAt);
 
 // Request DTOs — narrow: server-controlled fields (status, ids, timestamps)
 // are intentionally excluded to prevent over-posting (02-SECURITY B.6 / C.1). ----
@@ -18,11 +22,21 @@ public sealed record ItemTypeDto(
 public sealed class CreateItemTypeRequest
 {
     [Required, StringLength(200)] public string Name { get; set; } = string.Empty;
+
+    /// <summary>Omitted ⇒ false, i.e. plain-text values. See <see cref="ItemTypeDto"/>.</summary>
+    public bool IsMeasurable { get; set; }
 }
 
 public sealed class UpdateItemTypeRequest
 {
     [Required, StringLength(200)] public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Nullable on purpose: a plain <c>bool</c> binds an absent property as <c>false</c>, so any
+    /// client that PUT only a name — as the item-types screen used to — would silently clear the
+    /// flag on every rename. Omitting this field <b>preserves</b> the stored value.
+    /// </summary>
+    public bool? IsMeasurable { get; set; }
 }
 
 public sealed class UpdateItemTypeStatusRequest

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

@@ -19,6 +19,11 @@ public sealed class ItemTypeConfiguration : IEntityTypeConfiguration<ItemType>
         builder.Property(t => t.Name).IsRequired().HasMaxLength(200);
         builder.HasIndex(t => t.Name).IsUnique();
 
+        // false is the only safe default here: EF uses the CLR default as its "unset" sentinel,
+        // so if the store default were true, inserting an explicit false would be mistaken for
+        // "not set" and silently written as true. Sentinel and store default must agree.
+        builder.Property(t => t.IsMeasurable).IsRequired().HasDefaultValue(false);
+
         builder.Property(t => t.Status)
             .HasConversion<string>().HasMaxLength(20).IsRequired()
             .HasDefaultValue(EntityStatus.Active);

Backend/ERPCore/Services/ItemTypeService.cs

@@ -41,7 +41,7 @@ public sealed class ItemTypeService : IItemTypeService
         var total = await q.CountAsync(ct);
         var rows = await q.OrderBy(t => t.Name)
             .Skip(query.Skip).Take(query.PageSize)
-            .Select(t => new ItemTypeDto(t.ItemTypeId, t.Name, t.Status, t.CreatedAt, t.UpdatedAt))
+            .Select(t => new ItemTypeDto(t.ItemTypeId, t.Name, t.IsMeasurable, t.Status, t.CreatedAt, t.UpdatedAt))
             .ToListAsync(ct);
 
         return PagedResponse<ItemTypeDto>.Create(rows, query.Page, query.PageSize, total);
@@ -63,6 +63,7 @@ public sealed class ItemTypeService : IItemTypeService
         var itemType = new ItemType
         {
             Name = name,
+            IsMeasurable = request.IsMeasurable,
             Status = EntityStatus.Active,
             CreatedAt = DateTime.UtcNow
         };
@@ -90,6 +91,9 @@ public sealed class ItemTypeService : IItemTypeService
         // Renaming does not touch existing items: their SKUs already encode the values that
         // were chosen, and nothing joins back to this row (docs/10 Part C.9).
         itemType.Name = name;
+        // Omitted ⇒ keep what is stored. A plain bool would bind an absent property as false and
+        // so let a name-only PUT silently clear the flag on every rename.
+        itemType.IsMeasurable = request.IsMeasurable ?? itemType.IsMeasurable;
         itemType.UpdatedAt = DateTime.UtcNow;
 
         try
@@ -114,5 +118,5 @@ public sealed class ItemTypeService : IItemTypeService
         await _uow.SaveChangesAsync(ct);
     }
 
-    private static ItemTypeDto Map(ItemType t) => new(t.ItemTypeId, t.Name, t.Status, t.CreatedAt, t.UpdatedAt);
+    private static ItemTypeDto Map(ItemType t) => new(t.ItemTypeId, t.Name, t.IsMeasurable, t.Status, t.CreatedAt, t.UpdatedAt);
 }