- Detects codex CLI (via 'which codex' + --version) and Desktop (via /opt/codex-desktop/start.sh)
- Shows green ✔ or yellow ✘ status bar on main page
- 'Install' button opens guide dialog with install commands
- Desktop/CLI launch buttons disabled when corresponding tool is missing
- Dependency status logged on startup
- _set_busy respects missing-state (won't re-enable disabled buttons)
- Rebuilt .deb as v2.0.1
- Added CHANGELOG constant to launcher with version history
- Added 'Changelog' button to header bar (opens formatted dialog)
- Title bar now shows version number (v2.0.0)
- Added CHANGELOG.md to repo root
- Rebuilt .deb with latest sources