add support for for local TTS (e.g.: KokoroTTS)

[mowtschan]

TTS Integration for WritingTools

Add text-to-speech capability to WritingTools by integrating local TTS engines like KokoroTTS. This feature would allow users to listen to their selected text through a simple workflow:

How it works:

1. User selects text in any application
2. Triggers WritingTools with TTS option
3. Selected text is sent to local TTS endpoint (e.g., http://localhost:8880/v1)
4. Audio is streamed back and played automatically

Benefits:

• Privacy-first: All processing happens locally, no text sent to cloud services
• Universal: Works across all applications where WritingTools operates
• Flexible: Support for any TTS engine that provides an HTTP endpoint (KokoroTTS, Coqui TTS, Piper, etc.)
• Seamless: Integrates naturally into the existing WritingTools menu

Implementation approach:

• Add "Read Aloud" option to WritingTools menu
• Configure TTS endpoint URL in settings
• Handle API communication (POST request with text, receive audio response)
• Simple audio playback integration
• Optional: voice selection, speed controls, pause/resume

This would make WritingTools a complete writing assistant - not just for editing text, but also for consuming it through audio.