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/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
+}