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>

app/api/v1/admin/__init__.py

@@ -2,16 +2,11 @@
 """
 Admin API router aggregation.
 
-This module combines legacy admin routes with auto-discovered module routes.
+This module combines auto-discovered module routes for the admin API.
 
-LEGACY ROUTES (defined in app/api/v1/admin/):
-- /menu-config/* - Navigation configuration (super admin)
-- /modules/* - Module management (super admin)
-- /module-config/* - Module settings (super admin)
-
-AUTO-DISCOVERED MODULE ROUTES:
-- tenancy: auth, admin_users, users, companies, platforms, vendors, vendor_domains
-- core: dashboard, settings
+All admin routes are now auto-discovered from modules:
+- tenancy: auth, admin_users, users, companies, platforms, vendors, vendor_domains, modules, module_config
+- core: dashboard, settings, menu_config
 - messaging: messages, notifications, email-templates
 - monitoring: logs, tasks, tests, code_quality, audit, platform-health
 - billing: subscriptions, invoices, payments
@@ -30,44 +25,18 @@ IMPORTANT:
 
 from fastapi import APIRouter
 
-# Import all admin routers (legacy routes that haven't been migrated to modules)
-# NOTE: Migrated to modules (auto-discovered):
-#   - tenancy: auth, admin_users, users, companies, platforms, vendors, vendor_domains
-#   - core: dashboard, settings
-#   - messaging: messages, notifications, email_templates
-#   - monitoring: logs, tasks, tests, code_quality, audit, platform_health
-#   - cms: content_pages, images, media, vendor_themes
-from . import (
-    menu_config,
-    module_config,
-    modules,
-)
 
 # Create admin router
 router = APIRouter()
 
 
-# ============================================================================
-# Framework Config (remain in legacy - super admin only)
-# ============================================================================
-
-# Include menu configuration endpoints (super admin only)
-router.include_router(menu_config.router, tags=["admin-menu-config"])
-
-# Include module management endpoints (super admin only)
-router.include_router(modules.router, tags=["admin-modules"])
-
-# Include module configuration endpoints (super admin only)
-router.include_router(module_config.router, tags=["admin-module-config"])
-
-
 # ============================================================================
 # Auto-discovered Module Routes
 # ============================================================================
-# Routes from self-contained modules are auto-discovered and registered.
-# Modules include: billing, inventory, orders, marketplace, cms, customers,
-# monitoring (logs, tasks, tests, code_quality, audit, platform_health),
-# messaging (messages, notifications, email_templates)
+# All routes from self-contained modules are auto-discovered and registered.
+# Legacy routes have been migrated to their respective modules:
+# - menu_config -> core module
+# - modules, module_config -> tenancy module
 
 from app.modules.routes import get_admin_api_routes