fix(inventory): enable smart warehouse stock binding and optional brand/specs for inter-project transfer

backend/app/services/project_transfer_service.py

@@ -100,6 +100,56 @@ async def create_project_transfer(
             specs_hash,
             for_update=True,
         )
+
+        # Smart fallback: If exact hash or brand didn't match, check candidate rows in this warehouse for this material
+        if source_item is None:
+            candidates_res = await db.execute(
+                select(InventoryItem)
+                .where(
+                    InventoryItem.warehouse_id == payload.from_warehouse_id,
+                    InventoryItem.material_id == payload.material_id,
+                )
+                .with_for_update()
+            )
+            candidates = candidates_res.scalars().all()
+
+            if len(candidates) == 1:
+                source_item = candidates[0]
+            elif len(candidates) > 1:
+                best_cand = None
+                best_score = -1
+                p_keys = set(specs.keys())
+                p_vals = set(str(v).strip() for v in specs.values() if str(v).strip())
+
+                for cand in candidates:
+                    score = 0
+                    if cand.brand_id == payload.brand_id:
+                        score += 10
+                    elif cand.brand_id is None and payload.brand_id is None:
+                        score += 10
+                    elif cand.brand_id is None:
+                        score += 4
+
+                    c_specs = cand.specs or {}
+                    c_keys = set(c_specs.keys())
+                    c_vals = set(str(v).strip() for v in c_specs.values() if str(v).strip())
+
+                    for pk in p_keys:
+                        if pk in c_keys or f"spec_{pk}" in c_keys or any(pk in ck for ck in c_keys):
+                            score += 5
+                    for pv in p_vals:
+                        if pv in c_vals or any(pv in str(cv) for cv in c_vals):
+                            score += 5
+
+                    if cand.quantity >= payload.quantity:
+                        score += 2
+
+                    if score > best_score:
+                        best_score = score
+                        best_cand = cand
+
+                source_item = best_cand
+
         if source_item is None or source_item.quantity < payload.quantity:
             avail = source_item.quantity if source_item else Decimal("0")
             raise ValidationError(
@@ -129,16 +179,20 @@ async def create_project_transfer(
         db.add(out_tx)
         await db.flush()
 
+        actual_brand_id = source_item.brand_id
+        actual_specs = source_item.specs if source_item.specs is not None else specs
+        actual_specs_hash = source_item.specs_hash or canonical_specs_hash(actual_specs)
+
         transfer = ProjectTransfer(
             from_project_id=from_wh.project_id,
             from_warehouse_id=from_wh.id,
             to_project_id=payload.to_project_id,
             material_id=payload.material_id,
-            brand_id=payload.brand_id,
-            unit_id=payload.unit_id,
+            brand_id=actual_brand_id,
+            unit_id=source_item.unit_id if source_item.unit_id else payload.unit_id,
             quantity=payload.quantity,
-            specs=specs,
-            specs_hash=specs_hash,
+            specs=actual_specs,
+            specs_hash=actual_specs_hash,
             note=payload.note,
             status="in_transit",
             out_transaction_id=out_tx.id,