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/dev_tools/definition.py

@@ -85,20 +85,8 @@ dev_tools_module = ModuleDefinition(
     schemas_path="app.modules.dev_tools.schemas",
     exceptions_path="app.modules.dev_tools.exceptions",
     tasks_path="app.modules.dev_tools.tasks",
-    # =========================================================================
-    # Scheduled Tasks
-    # =========================================================================
     # Note: Code quality and test tasks are on-demand, not scheduled.
-    # If scheduled scans are desired, they can be added here:
-    # scheduled_tasks=[
-    #     ScheduledTask(
-    #         name="dev_tools.nightly_code_scan",
-    #         task="app.modules.dev_tools.tasks.code_quality.execute_code_quality_scan",
-    #         schedule="0 2 * * *",  # Daily at 02:00
-    #         options={"queue": "long_running"},
-    #     ),
-    # ],
-    scheduled_tasks=[],
+    # If scheduled scans are desired, add ScheduledTask entries here.
 )