feat: add Admin UI for platform module management (Phase 5)

Added a complete Admin UI for managing platform modules:

API endpoints (app/api/v1/admin/modules.py):
- GET /modules - List all available modules
- GET /modules/platforms/{id} - Get platform modules
- PUT /modules/platforms/{id} - Update enabled modules
- POST /modules/platforms/{id}/enable - Enable a module
- POST /modules/platforms/{id}/disable - Disable a module
- POST /modules/platforms/{id}/enable-all - Enable all
- POST /modules/platforms/{id}/disable-optional - Core only

Admin UI:
- New page route: /admin/platforms/{code}/modules
- Template: platform-modules.html
- JavaScript: platform-modules.js
- Link added to platform-detail.html Super Admin section

Features:
- Toggle modules on/off with dependency resolution
- Enable all / Core only bulk actions
- Visual dependency indicators
- Separate sections for core vs optional modules
- Feature list preview per module

Also includes require_menu_access updates to page routes from Phase 2.

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

app/api/v1/admin/__init__.py

@@ -61,6 +61,7 @@ from . import (
     media,
     menu_config,
     messages,
+    modules,
     monitoring,
     notifications,
     order_item_exceptions,
@@ -125,6 +126,9 @@ router.include_router(platforms.router, tags=["admin-platforms"])
 # 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"])
+
 
 # ============================================================================
 # User Management