inventory_vehicle_compat.get_compatibility was trying to JOIN tenant
inventory_vehicle_compat with master tables (model_year_engine, brands,
models, years, engines) on a single tenant connection. Those tables only
exist in the master DB, causing the query to fail silently.
Fix: split into two queries:
1. Fetch MYE IDs from tenant's inventory_vehicle_compat
2. Resolve vehicle details from master DB via ANY(%s)
3. Merge results
Also fixes the argument mismatch: inventory_bp passed (tenant, master,
item_id) but the function only accepted 2 args.