Electron App: Theming system

[jongio]

Overview

CSS variable-based theming with 5 built-in themes, Windows Terminal theme detection, and dark/light mode support.

Acceptance Criteria

• CSS custom properties for all theme colors (bg, fg, accent, borders, etc.)
• 5 built-in themes matching TUI: Dispatch Dark, Dispatch Light, Campbell, One Half Dark, One Half Light
• Theme switching via settings (immediate, no reload)
• Auto theme: detect system dark/light preference, adapt accordingly
• Windows Terminal theme detection: parse settings.json for active color scheme
• Theme colors map to attention dots, status indicators, conversation bubbles
• High contrast mode (system accessibility setting detection)
• Smooth theme transition (CSS transitions on color changes)
• Theme preview in settings panel

Color Tokens

\\css
:root {
--bg-primary, --bg-secondary, --bg-tertiary
--fg-primary, --fg-secondary, --fg-muted
--accent-primary, --accent-secondary
--border-primary, --border-subtle
--attention-working, --attention-thinking, --attention-waiting, ...
--conversation-user-bg, --conversation-assistant-bg
--selection-bg, --hover-bg, --focus-ring
}
\\

Notes

• Theme definitions in JSON (importable, same structure as TUI builtins.go)
• Custom themes: user can drop JSON files in config directory
• Nerd Font detection: check if font has ligatures/icons, show rich icons vs fallback