feat: add module definition completeness validation and permissions

Add new validation rules MOD-020 to MOD-023 for module definition
completeness and standardize permissions across all modules.

Changes:
- Add MOD-020: Module definitions must have required attributes
- Add MOD-021: Modules with menus should have features
- Add MOD-022: Feature modules should have permissions
- Add MOD-023: Modules with routers should use get_*_with_routers pattern

Module permissions added:
- analytics: view, export, manage_dashboards
- billing: view_tiers, manage_tiers, view_subscriptions, manage_subscriptions, view_invoices
- cart: view, manage
- checkout: view_settings, manage_settings
- cms: view_pages, manage_pages, view_media, manage_media, manage_themes
- loyalty: view_programs, manage_programs, view_rewards, manage_rewards
- marketplace: view_integration, manage_integration, sync_products
- messaging: view_messages, send_messages, manage_templates
- payments: view_gateways, manage_gateways, view_transactions

Module improvements:
- Complete cart module with features and permissions
- Complete checkout module with features and permissions
- Add features to catalog module
- Add version to cms module
- Fix loyalty platform_router attachment
- Add path definitions to payments module
- Remove empty scheduled_tasks from dev_tools module

Documentation:
- Update module-system.md with new validation rules
- Update architecture-rules.md with MOD-020 to MOD-023

Tests:
- Add unit tests for module definition completeness
- Add tests for permission structure validation

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

app/modules/marketplace/definition.py

@@ -8,7 +8,7 @@ dependencies, route configurations, and scheduled tasks.
 Note: This module requires the inventory module to be enabled.
 """
 
-from app.modules.base import MenuItemDefinition, MenuSectionDefinition, ModuleDefinition, ScheduledTask
+from app.modules.base import MenuItemDefinition, MenuSectionDefinition, ModuleDefinition, PermissionDefinition, ScheduledTask
 from app.modules.enums import FrontendType
 
 
@@ -43,6 +43,27 @@ marketplace_module = ModuleDefinition(
         "order_import",  # Import orders from marketplace
         "marketplace_analytics",  # Marketplace performance metrics
     ],
+    # Module-driven permissions
+    permissions=[
+        PermissionDefinition(
+            id="marketplace.view_integration",
+            label_key="marketplace.permissions.view_integration",
+            description_key="marketplace.permissions.view_integration_desc",
+            category="marketplace",
+        ),
+        PermissionDefinition(
+            id="marketplace.manage_integration",
+            label_key="marketplace.permissions.manage_integration",
+            description_key="marketplace.permissions.manage_integration_desc",
+            category="marketplace",
+        ),
+        PermissionDefinition(
+            id="marketplace.sync_products",
+            label_key="marketplace.permissions.sync_products",
+            description_key="marketplace.permissions.sync_products_desc",
+            category="marketplace",
+        ),
+    ],
     menu_items={
         FrontendType.ADMIN: [
             "marketplace-letzshop",  # Marketplace monitoring