Detect dark/light mode before React hydrates to eliminate the visible
white-to-dark flash when opening windows in dark mode.
Frontend:
- Inline script now reads next-themes localStorage key and applies
.dark class, colorScheme, and backgroundColor on <html> before first
paint
- Add CSS-only fallback via prefers-color-scheme media query in an
inline <style> tag that fires before any JS executes
macOS backend:
- Detect system dark mode via `defaults read -g AppleInterfaceStyle`
(cached with OnceLock) and set native window background color to
match dark theme in apply_platform_window_style
- Persist user appearance mode preference (dark/light/system) to DB
alongside zoom level so new windows use the correct background
- Add update_appearance_mode Tauri command; frontend syncs on mount,
on settings change, and on cross-window storage events
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
