- login(): check platformRoles before membership validation; fallback to first active tenant for superset admins
- refreshTokens(): allow refresh for superset admins even without memberships
- tenantMiddleware: skip tenantPool resolution when tenantId is empty for superset admins
- Add metabase.service.ts for automatic DB registration
- Hook createTenant, addTenantToOwner and deleteTenant to sync with Metabase
- Keep all existing features from latest version