refactor: complete module-driven architecture migration

This commit completes the migration to a fully module-driven architecture:

## Models Migration
- Moved all domain models from models/database/ to their respective modules:
  - tenancy: User, Admin, Vendor, Company, Platform, VendorDomain, etc.
  - cms: MediaFile, VendorTheme
  - messaging: Email, VendorEmailSettings, VendorEmailTemplate
  - core: AdminMenuConfig
- models/database/ now only contains Base and TimestampMixin (infrastructure)

## Schemas Migration
- Moved all domain schemas from models/schema/ to their respective modules:
  - tenancy: company, vendor, admin, team, vendor_domain
  - cms: media, image, vendor_theme
  - messaging: email
- models/schema/ now only contains base.py and auth.py (infrastructure)

## Routes Migration
- Moved admin routes from app/api/v1/admin/ to modules:
  - menu_config.py -> core module
  - modules.py -> tenancy module
  - module_config.py -> tenancy module
- app/api/v1/admin/ now only aggregates auto-discovered module routes

## Menu System
- Implemented module-driven menu system with MenuDiscoveryService
- Extended FrontendType enum: PLATFORM, ADMIN, VENDOR, STOREFRONT
- Added MenuItemDefinition and MenuSectionDefinition dataclasses
- Each module now defines its own menu items in definition.py
- MenuService integrates with MenuDiscoveryService for template rendering

## Documentation
- Updated docs/architecture/models-structure.md
- Updated docs/architecture/menu-management.md
- Updated architecture validation rules for new exceptions

## Architecture Validation
- Updated MOD-019 rule to allow base.py in models/schema/
- Created core module exceptions.py and schemas/ directory
- All validation errors resolved (only warnings remain)

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

main.py

@@ -188,13 +188,23 @@ if MODULES_DIR.exists():
     for module_dir in sorted(MODULES_DIR.iterdir()):
         if not module_dir.is_dir():
             continue
+
+        module_name = module_dir.name
+
+        # Mount module static files
         module_static = module_dir / "static"
         if module_static.exists():
-            module_name = module_dir.name
             mount_path = f"/static/modules/{module_name}"
             app.mount(mount_path, StaticFiles(directory=str(module_static)), name=f"{module_name}_static")
             logger.info(f"Mounted module static files: {mount_path} -> {module_static}")
 
+        # Mount module locale files (for JS i18n)
+        module_locales = module_dir / "locales"
+        if module_locales.exists():
+            mount_path = f"/static/modules/{module_name}/locales"
+            app.mount(mount_path, StaticFiles(directory=str(module_locales)), name=f"{module_name}_locales")
+            logger.info(f"Mounted module locales: {mount_path} -> {module_locales}")
+
 # Mount main static directory AFTER module statics
 if STATIC_DIR.exists():
     app.mount("/static", StaticFiles(directory=str(STATIC_DIR)), name="static")