Refactor production and stock tests to remove UOM dependency

- Updated production.spec.ts, stock-adjustments.spec.ts, and stock-transfers.spec.ts to eliminate UOM references in API seeder and test cases.
- Adjusted ApiSeeder methods to remove UOM parameters from stock receiving and production template creation.
- Revised documentation to reflect changes in UOM handling, emphasizing that stock is counted in base UOM only.
- Introduced new enums for MeasureUnit and StageQtyUnit to clarify content size and stage input quantities.
- Implemented ItemContent service to validate and normalize content sizes.
- Updated smoke tests to validate production stage inputs expressed in content units, ensuring correct consumption calculations.
- Modified frontend UOM label handling to reflect the removal of per-line UOMs in document lines.

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

@@ -10,8 +10,6 @@ import {
   TrackingMode,
   UpdateItemReorderRequest,
   UpdateItemRequest,
-  UpdateUomConversionsRequest,
-  UpdateUomConversionsResponse,
 } from "@/types/master-data"
 
 export interface ListItemsParams {
@@ -59,11 +57,4 @@ export const itemsApi = {
       body: request,
     })
   },
-
-  updateUomConversions(itemId: number, request: UpdateUomConversionsRequest): Promise<UpdateUomConversionsResponse> {
-    return apiRequest<UpdateUomConversionsResponse>(`/items/${itemId}/uom-conversions`, {
-      method: "PUT",
-      body: request,
-    })
-  },
 }

Frontend/erp-system/lib/uom-label.ts

@@ -0,0 +1,46 @@
+// Document lines carry no UOM of their own: every quantity in the system is a count of the
+// item's base UOM (FR-MD-02/03). Screens that used to render a per-line UOM picker now show
+// the unit as a derived, read-only label — the user still needs to know that "12" means
+// 12 bottles, they just cannot change it.
+
+import { ItemListItem, Uom } from "@/types/master-data"
+
+/** Minimal shapes so this works with both `Item` and `ItemListItem`. */
+type ItemLike = Pick<ItemListItem, "itemId" | "baseUomId">
+
+/**
+ * Display name of an item's base UOM, e.g. "BOTTLE". Returns an em dash when no item is
+ * selected yet, and falls back to the raw id if the UOM list has not loaded.
+ */
+export function baseUomLabel(
+  items: readonly ItemLike[],
+  uoms: readonly Uom[],
+  itemId: number | null | undefined,
+): string {
+  if (!itemId) return "—"
+  const item = items.find((candidate) => candidate.itemId === itemId)
+  if (!item) return "—"
+  return uoms.find((u) => u.uomId === item.baseUomId)?.name ?? `#${item.baseUomId}`
+}
+
+/**
+ * Display name for a UOM id that may be absent — an intermediate production output's WIP
+ * label, which is null on any output that references a real item.
+ */
+export function uomLabel(uoms: readonly Uom[], uomId: number | null | undefined): string {
+  if (!uomId) return "—"
+  return uoms.find((u) => u.uomId === uomId)?.name ?? `#${uomId}`
+}
+
+/**
+ * The unit an item's content is measured in — "ml" or "g" — or null when the item has no
+ * content size. Used to label a production input entered in content units.
+ */
+export function contentUnitLabel(
+  items: readonly Pick<ItemListItem, "itemId" | "contentBaseUnit">[],
+  itemId: number | null | undefined,
+): string | null {
+  if (!itemId) return null
+  const unit = items.find((candidate) => candidate.itemId === itemId)?.contentBaseUnit
+  return unit ? unit.toLowerCase() : null
+}

Frontend/erp-system/lib/validations/grn.ts

@@ -13,7 +13,6 @@ export const grnHeaderSchema = z.object({
 
 export function validateLine(input: {
   itemId: number | null
-  uomId: number | null
   qty: string
   unitCost: string
   discountPct: string
@@ -25,7 +24,6 @@ export function validateLine(input: {
   const errors: Record<string, string> = {}
 
   if (!input.itemId) errors.itemId = "Select an item"
-  if (!input.uomId) errors.uomId = "Select a UOM"
 
   const qty = Number(input.qty)
   if (!input.qty || Number.isNaN(qty) || qty <= 0) errors.qty = "Quantity must be greater than 0"

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

@@ -10,12 +10,38 @@ export function validateItemForm(input: {
   name: string
   categoryId: number | null
   baseUomId: number | null
+  /** Raw field value; empty means "no measurable content", which is valid. */
+  contentQty?: string
+  contentUnit?: string | null
 }): Record<string, string> {
   const errors: Record<string, string> = {}
   if (!input.sku.trim()) errors.sku = "SKU is required"
   if (!input.name.trim()) errors.name = "Item name is required"
   if (!input.categoryId) errors.categoryId = "Select a category"
   if (!input.baseUomId) errors.baseUomId = "Select a base UOM"
+  Object.assign(errors, contentPairErrors(input.contentQty, input.contentUnit))
+  return errors
+}
+
+/**
+ * An item's content size is optional, but half of it is not: the server rejects a lone
+ * quantity or a lone unit with a 422. Shared because the variant builder validates its own
+ * shape and so cannot go through `validateItemForm`.
+ */
+export function contentPairErrors(
+  contentQty: string | undefined,
+  contentUnit: string | null | undefined,
+): Record<string, string> {
+  const errors: Record<string, string> = {}
+  const rawQty = (contentQty ?? "").trim()
+  const unit = contentUnit ?? null
+
+  if (rawQty && !unit) errors.contentUnit = "Select a unit for the content size"
+  if (!rawQty && unit) errors.contentQty = "Enter a content size, or clear the unit"
+  if (rawQty) {
+    const qty = Number(rawQty)
+    if (Number.isNaN(qty) || qty <= 0) errors.contentQty = "Content size must be greater than 0"
+  }
   return errors
 }
 
@@ -29,16 +55,6 @@ export function validateReorderLine(input: { warehouseId: number | null; reorder
   return errors
 }
 
-export function validateConversionLine(input: { fromUom: number | null; toUom: number | null; factor: string }): Record<string, string> {
-  const errors: Record<string, string> = {}
-  if (!input.fromUom) errors.fromUom = "Select a UOM"
-  if (!input.toUom) errors.toUom = "Select a UOM"
-  if (input.fromUom && input.toUom && input.fromUom === input.toUom) errors.toUom = "From and to UOM must differ"
-  const factor = Number(input.factor)
-  if (!input.factor || Number.isNaN(factor) || factor <= 0) errors.factor = "Factor must be greater than 0"
-  return errors
-}
-
 export function validateUomName(name: string): Record<string, string> {
   const errors: Record<string, string> = {}
   if (!name.trim()) errors.name = "UOM name is required"

Frontend/erp-system/lib/validations/procurement.ts

@@ -32,7 +32,6 @@ export function validateQuotationLine(input: { unitPrice: string; leadDays: stri
 
 export function validatePoLine(input: {
   itemId: number | null
-  uomId: number | null
   warehouseId: number | null
   qty: string
   unitPrice: string
@@ -40,7 +39,6 @@ export function validatePoLine(input: {
 }): Record<string, string> {
   const errors: Record<string, string> = {}
   if (!input.itemId) errors.itemId = "Select an item"
-  if (!input.uomId) errors.uomId = "Select a UOM"
   if (!input.warehouseId) errors.warehouseId = "Select a warehouse"
   const qty = Number(input.qty)
   if (!input.qty || Number.isNaN(qty) || qty <= 0) errors.qty = "Quantity must be greater than 0"