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/payments/definition.py

@@ -15,7 +15,7 @@ This separation allows:
 3. Orders without billing (customer payments only)
 """
 
-from app.modules.base import ModuleDefinition
+from app.modules.base import ModuleDefinition, PermissionDefinition
 from app.modules.enums import FrontendType
 
 
@@ -51,6 +51,27 @@ payments_module = ModuleDefinition(
         "bank_transfer",  # Bank transfer support
         "transaction_history",  # Transaction records
     ],
+    # Module-driven permissions
+    permissions=[
+        PermissionDefinition(
+            id="payments.view_gateways",
+            label_key="payments.permissions.view_gateways",
+            description_key="payments.permissions.view_gateways_desc",
+            category="payments",
+        ),
+        PermissionDefinition(
+            id="payments.manage_gateways",
+            label_key="payments.permissions.manage_gateways",
+            description_key="payments.permissions.manage_gateways_desc",
+            category="payments",
+        ),
+        PermissionDefinition(
+            id="payments.view_transactions",
+            label_key="payments.permissions.view_transactions",
+            description_key="payments.permissions.view_transactions_desc",
+            category="payments",
+        ),
+    ],
     menu_items={
         FrontendType.ADMIN: [
             "payment-gateways",  # Configure payment gateways
@@ -61,7 +82,14 @@ payments_module = ModuleDefinition(
     },
     is_core=False,
     is_internal=False,
-    is_self_contained=True,  # Enable auto-discovery from routes/api/
+    # =========================================================================
+    # Self-Contained Module Configuration
+    # =========================================================================
+    is_self_contained=True,
+    services_path="app.modules.payments.services",
+    models_path="app.modules.payments.models",
+    schemas_path="app.modules.payments.schemas",
+    exceptions_path="app.modules.payments.exceptions",
 )