Merge upstream/main: v0.1.61 updates with TOTP & password reset

Major features:
- feat(auth): add TOTP (2FA) support for enhanced security
- feat(auth): add password reset functionality
- feat(openai): improve rate limit handling with reset time tracking
- feat(subscription): add expiry notification service
- fix(urlvalidator): remove trailing slash from validated URLs
- docs: update demo site domain

Resolved conflicts:
- deploy/docker-compose.yml: added TOTP_ENCRYPTION_KEY config
- setting_service.go: keep TianShuAPI site name while adding new features

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

frontend/src/api/index.ts

@@ -7,7 +7,7 @@
 export { apiClient } from './client'
 
 // Auth API
-export { authAPI } from './auth'
+export { authAPI, isTotp2FARequired, type LoginResponse } from './auth'
 
 // User APIs
 export { keysAPI } from './keys'
@@ -15,6 +15,7 @@ export { usageAPI } from './usage'
 export { userAPI } from './user'
 export { redeemAPI, type RedeemHistoryItem } from './redeem'
 export { userGroupsAPI } from './groups'
+export { totpAPI } from './totp'
 
 // Admin APIs
 export { adminAPI } from './admin'