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.

frontend/src/lib/api.ts

@@ -1675,7 +1675,8 @@ export const apiV26 = {
       const d = await postData<Parameters<typeof rawWarehouse>[0]>(`/inventory/warehouses${projectQuery()}`, body);
       return rawWarehouse(d);
     },
-    update: async (id: string, body: { name?: string; description?: string | null; project_id?: string }): Promise<Warehouse> => {
+    // project_id عمداً در تایپ نیست — انبار برای همیشه به پروژه‌ی والدش تعلق دارد
+    update: async (id: string, body: { name?: string; description?: string | null }): Promise<Warehouse> => {
       const d = await patchData<Parameters<typeof rawWarehouse>[0]>(`/inventory/warehouses/${id}${projectQuery()}`, body);
       return rawWarehouse(d);
     },