fix trigger creation bug

backend/models.py

@@ -199,10 +199,10 @@ class ProductHistory(Base):
     operation = Column(String(1), nullable=False)  # 'U' for Update, 'D' for Delete
     archived_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
 
-# Create trigger after ProductHistory table is created
-@event.listens_for(ProductHistory.__table__, 'after_create')
-def create_products_versioning_trigger(target, connection, **kw):
-    """Create the products versioning trigger after the history table is created"""
+# Create trigger after ALL tables are created
+@event.listens_for(Base.metadata, 'after_create')
+def create_products_versioning_trigger_after_all_tables(target, connection, **kw):
+    """Create the products versioning trigger after all tables are created"""
     try:
         connection.execute(text(PRODUCTS_VERSIONING_TRIGGER_SQL))
         print("✅ Products versioning trigger created successfully")