Select the version in the interface. 
RVC is not supported on AllTalk V1

1. Core Feature Addition:
   - Added AllTalk V1/V2 server version selection
   - Added RVC (Realistic Voice Conversion) support for V2
   - RVC features are automatically disabled when V1 is selected

2. Code Improvements:
   - Replaced custom debounce implementation with shared utils.js debounce utility
   - Fixed linting issues:
     - Converted HTML attribute quotes in template literals to single quotes
     - Added trailing commas where required
     - Fixed console.error message formatting

3. New Settings/Properties Added:
   ```javascript
   server_version: 'v2' (default)
   rvc_character_voice: 'Disabled'
   rvc_character_pitch: '0'
   rvc_narrator_voice: 'Disabled'
   rvc_narrator_pitch: '0'
   ```

4. Bug Fixes/Improvements:
   - Better error handling for RVC voice fetching
   - Improved URL handling for V1/V2 differences in API responses
   - Enhanced settings initialization and validation

5. Structural Changes:
   - Added RVC-specific UI elements and controls
   - Added version-specific logic for API endpoints
   - Improved settings synchronization between UI and backend

**NOTE** On line 70 there is an eslint bypass:

```javascript
        // HTML template literals can trigger ESLint quotes warnings when quotes are used in HTML attributes.
        // Disabling quotes rule for this one line as it's a false positive with HTML template literals.
        // eslint-disable-next-line quotes
        let html = `<div class="at-settings-separator">AllTalk V2 Settings</div>`;
```

The reason is:
1. ESLint's quotes rule wants all strings to use single quotes
2. However, this is a template literal containing HTML, where double quotes are standard for attributes
3. I tried various solutions:
   - Using single quotes: `<div class='at-settings-separator'>`
   - Using double quotes: `<div class="at-settings-separator">`
   - Even tried escaping quotes
   But ESLint just kept flagging it as an error