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.

Backend/smoke/m5_receipt.py

@@ -157,18 +157,18 @@ def main():
                    if i["itemId"] == raw)
     finished_b = state["finishedItemId"]
 
-    # A fresh single-stage template: base-UOM input so no conversion muddies the arithmetic,
-    # qtyPerBatch 3.5 so the consumed quantity is NOT a multiple of the target (which is what
+    # A fresh single-stage template: a pack-counted input, so no content division muddies
+    # the arithmetic; qtyPerBatch 3.5 so consumed is NOT a multiple of the target (which is what
     # forces pool / goodQty to repeat).
     payload_b = {
         "code": BIG_TEMPLATE_CODE, "name": "Smoke M5 rounding line",
         "stages": [{
             "key": "tmp-b", "name": "Mix", "estimatedMinutes": 5, "posX": 0, "posY": 0,
             "fieldDefs": [],
-            "inputs": [{"source": "Stock", "itemId": raw, "uomId": raw_uom,
+            "inputs": [{"source": "Stock", "itemId": raw,
                         "qtyPerBatch": BIG_QTY_PER_BATCH}],
             "outputs": [{"key": "tmp-bo", "name": "Mixed", "itemId": finished_b,
-                         "uomId": raw_uom, "qtyPerBatch": 1}],
+                         "qtyPerBatch": 1}],
         }],
         "edges": [],
     }
@@ -190,7 +190,7 @@ def main():
         # and the pool would not match the figures this section reasons about — the assertions
         # would still "pass" while testing something else entirely.
         drain_stock(c, wh)
-        seed_costed_stock(c, wh, [(raw, raw_uom, 5000, BIG_UNIT_COST)])
+        seed_costed_stock(c, wh, [(raw, 5000, BIG_UNIT_COST)])
 
         big = c.post("/production-runs", {"templateId": tid, "targetQty": BIG_TARGET, "warehouseId": wh})
         if big.status != 201:
@@ -243,7 +243,7 @@ def main():
                 "key": "tmp-one", "name": "Make", "estimatedMinutes": 1, "posX": 0, "posY": 0,
                 "fieldDefs": [], "inputs": [],
                 "outputs": [{"key": "tmp-o", "name": "Tracked", "itemId": tracked["itemId"],
-                             "uomId": tracked["baseUomId"], "qtyPerBatch": 1}],
+                             "qtyPerBatch": 1}],
             }],
             "edges": [],
         }