Customizable color theme #2
Description
The diff colors (green/red for additions/removals) are currently hardcoded. Users should be able to customize the color scheme.
Desired behavior:
- Support light and dark themes
- Allow custom colors for additions, deletions, and modifications
- Persist theme preference across sessions
- Bonus: import VS Code color themes
Tech context: Monaco Editor supports custom themes via monaco.editor.defineTheme(). Tauri has a store plugin for persisting preferences.