Add AI translation feature

[r1di]

AI Translation Feature Summary

1. Chapter Translation:

   • Ability to translate single or multiple chapters using AI
   • Local storage and management of translations
   • Toggle functionality to show/hide translations in the reader

2. Translation Service:

   • Integration with AI translation APIs
   • Support for various AI models
   • Batch processing for multiple chapters

3. Database Integration:

   • New TranslationTable for storing translations
   • Links to the existing chapter database system

4. User Interface:

   • Dedicated translation settings with model selection
   • Translation list management screen
   • Reader UI integration for immediate access

5. Settings:

   • API key configuration
   • Model selection
   • Default translation instructions