fix: correct module definitions for cart, catalog, checkout

- Fix cart to import from app.modules.base instead of non-existent
  app.modules.core.module_registry
- Change 'dependencies' to 'requires' (correct attribute name)
- Remove invalid 'provides_*' attributes that don't exist in
  ModuleDefinition dataclass

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/cart/definition.py

@@ -6,7 +6,7 @@ This module provides shopping cart functionality for customer storefronts.
 It is session-based and does not require customer authentication.
 """
 
-from app.modules.core.module_registry import ModuleDefinition
+from app.modules.base import ModuleDefinition
 
 module = ModuleDefinition(
     code="cart",
@@ -14,12 +14,5 @@ module = ModuleDefinition(
     description="Session-based shopping cart for storefronts",
     version="1.0.0",
     is_self_contained=True,
-    dependencies=["inventory"],  # Checks inventory availability
-    provides_models=True,
-    provides_schemas=True,
-    provides_services=True,
-    provides_api_routes=True,
-    provides_page_routes=False,
-    provides_admin_ui=False,
-    provides_vendor_ui=False,
+    requires=["inventory"],  # Checks inventory availability
 )