feat(inventory)!: lock warehouses permanently to their parent project

Warehouses now belong strictly and exclusively to the project they were created under; cross-project reassignment is removed end-to-end.

Backend: PATCH /inventory/warehouses/{id} no longer applies project_id — any attempt to move a warehouse to a different project returns 400 with «پروژه‌ی انبار قابل تغییر نیست — انبار برای همیشه به پروژه‌ی والدش تعلق دارد» (sending the current project stays a harmless no-op). The WarehouseUpdate schema documents project_id as accept-only-to-reject; creation still requires project_id and delete is unchanged.

Frontend: the Organization page's per-warehouse project dropdown («انتقال به پروژه دیگر») and its moveWarehouse handler are removed — warehouses render statically inside their project card with only the dashboard link and delete; the warehouses.update API type no longer accepts project_id. WarehousesPage already had no move UI (rename/describe only).

Verified end-to-end against the running stack: rename 200; same-project project_id no-op 200; cross-project reassignment 400 with the guard message; warehouse remains in its original project; test data cleaned up. python compile + api/frontend builds clean.

backend/app/routers/inventory.py

@@ -271,12 +271,13 @@ async def update_warehouse(
         wh.name = payload.name
     if payload.description is not None:
         wh.description = payload.description
+    # پروژه‌ی انبار تغییرناپذیر است — انبار برای همیشه به پروژه‌ی والدش تعلق
+    # دارد و فقط با حذف و ساخت دوباره می‌تواند جابه‌جا شود.
     if payload.project_id is not None and str(payload.project_id) != str(wh.project_id):
-        if await db.get(Project, payload.project_id) is None:
-            raise NotFoundError("پروژه مقصد یافت نشد", field="project_id")
-        if scope.role == ROLE_PM and payload.project_id != scope.project_id:
-            raise ForbiddenError("PM فقط می‌تواند انبار را در پروژه خودش جابه‌جا کند", field="project_id")
-        wh.project_id = payload.project_id
+        raise ValidationError(
+            "پروژه‌ی انبار قابل تغییر نیست — انبار برای همیشه به پروژه‌ی والدش تعلق دارد",
+            field="project_id",
+        )
     await db.flush()
     return {"data": warehouse_to_dict(wh, await db.get(Project, wh.project_id))}