feat: update README and Settings page for dual backend support and Aliyun API key management

README.md

@@ -9,6 +9,7 @@ A text-to-speech web application based on Qwen3-TTS, supporting custom voice, vo
 - Custom Voice: Predefined speaker voices
 - Voice Design: Create voices from natural language descriptions
 - Voice Cloning: Clone voices from uploaded audio
+- Dual Backend Support: Switch between local model and Aliyun TTS API
 - JWT auth, async tasks, voice cache, dark mode
 
 ## Tech Stack
@@ -26,7 +27,9 @@ python -m venv venv
 source venv/bin/activate
 pip install -r requirements.txt
 cp .env.example .env
-# Edit .env to configure MODEL_BASE_PATH etc.
+# Edit .env to configure MODEL_BASE_PATH and DEFAULT_BACKEND
+# For local model: Ensure MODEL_BASE_PATH points to Qwen model directory
+# For Aliyun: Set DEFAULT_BACKEND=aliyun and configure API key in web settings
 uvicorn main:app --host 0.0.0.0 --port 8000 --reload
 ```
 
@@ -49,6 +52,8 @@ Visit `http://localhost:5173`
 
 ## Configuration
 
+### Backend Configuration
+
 Backend `.env` key settings:
 
 ```env
@@ -56,26 +61,75 @@ SECRET_KEY=your-secret-key
 MODEL_DEVICE=cuda:0
 MODEL_BASE_PATH=../Qwen
 DATABASE_URL=sqlite:///./qwen_tts.db
+
+DEFAULT_BACKEND=local
+
+ALIYUN_REGION=beijing
+ALIYUN_MODEL_FLASH=qwen3-tts-flash-realtime
+ALIYUN_MODEL_VC=qwen3-tts-vc-realtime-2026-01-15
+ALIYUN_MODEL_VD=qwen3-tts-vd-realtime-2026-01-15
 ```
 
+**Backend Options:**
+
+- `DEFAULT_BACKEND`: Default TTS backend, options: `local` or `aliyun`
+- **Local Mode**: Uses local Qwen3-TTS model (requires `MODEL_BASE_PATH` configuration)
+- **Aliyun Mode**: Uses Aliyun TTS API (requires users to configure their API keys in settings)
+
+**Aliyun Configuration:**
+
+- Users need to add their Aliyun API keys in the web interface settings page
+- API keys are encrypted and stored securely in the database
+- Superuser can enable/disable local model access for all users
+- To obtain an Aliyun API key, visit the [Aliyun Console](https://dashscope.console.aliyun.com/)
+
+### Frontend Configuration
+
 Frontend `.env`:
 
 ```env
 VITE_API_URL=http://localhost:8000
 ```
 
+## Usage
+
+### Switching Between Backends
+
+1. Log in to the web interface
+2. Navigate to Settings page
+3. Configure your preferred backend:
+   - **Local Model**: Select "本地模型" (requires local model to be enabled by superuser)
+   - **Aliyun API**: Select "阿里云" and add your API key
+4. The selected backend will be used for all TTS operations by default
+5. You can also specify a different backend per request using the `backend` parameter in the API
+
+### Managing Aliyun API Key
+
+1. In Settings page, find the "阿里云 API 密钥" section
+2. Enter your Aliyun API key
+3. Click "更新密钥" to save and validate
+4. The system will verify the key before saving
+5. You can delete the key anytime using the delete button
+
 ## API
 
 ```
 POST /auth/register          - Register
 POST /auth/token             - Login
-POST /tts/custom-voice       - Custom voice
-POST /tts/voice-design       - Voice design
-POST /tts/voice-clone        - Voice cloning
+POST /tts/custom-voice       - Custom voice (supports backend parameter)
+POST /tts/voice-design       - Voice design (supports backend parameter)
+POST /tts/voice-clone        - Voice cloning (supports backend parameter)
 GET  /jobs                   - Job list
 GET  /jobs/{id}/download     - Download result
 ```
 
+**Backend Parameter:**
+
+All TTS endpoints support an optional `backend` parameter to specify the TTS backend:
+- `backend: "local"` - Use local Qwen3-TTS model
+- `backend: "aliyun"` - Use Aliyun TTS API
+- If not specified, uses the user's default backend setting
+
 ## License
 
 Apache-2.0 license