Fix: only sync ML stock when both marketplace_listings and meli_sync_queue exist

pos/services/inventory_engine.py

@@ -125,12 +125,11 @@ def record_operation(conn, inventory_id, branch_id, operation_type, quantity,
     # Queue ML stock sync if this product has an active ML listing.
     # Skip gracefully if the marketplace tables do not exist in this tenant.
     cur.execute("""
-        SELECT 1 FROM information_schema.tables
+        SELECT COUNT(*) FROM information_schema.tables
         WHERE table_schema = 'public'
           AND table_name IN ('marketplace_listings', 'meli_sync_queue')
-        LIMIT 1
     """)
-    if cur.fetchone():
+    if cur.fetchone()[0] >= 2:
         cur.execute("""
             INSERT INTO meli_sync_queue (inventory_id, action, status)
             SELECT %s, 'stock_update', 'pending'