- Seed default RBAC roles per store and assign role_id to StoreUser
records (was never implemented after RBAC Phase 1 cleanup)
- Handle nullable role in auth_service find_user_store and
get_user_store_role to prevent NoneType crash on login
- Use platform_clean_path instead of clean_path in FrontendTypeMiddleware
so /store/X/dashboard is detected as STORE, not STOREFRONT
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>