- Change crowdin.yml to use %locale_with_underscore% for proper zh_CN/zh_TW handling
- Add sectionLanguage, appearanceLanguage, appearanceLanguageSubtitle to app_en.arb
- Add app_zh_CN.arb for Simplified Chinese (Crowdin target)
- Update .gitignore to exclude log files and tool/ folder
- Regenerate localization dart files
- Add extension manager, manifest, runtime, providers, settings
- Add extension provider and UI pages (extensions, detail, priority)
- Add download service picker widget
- Add metadata provider priority page
- Add source field to Track model for extension tracking
- Add skipBuiltInFallback manifest option to skip built-in providers
- Update download queue to use source extension first
- Add extension upgrade support without data loss
zarzet