- Add username/password login as additional auth mechanism alongside existing token
- First login must use token; password can be configured in Settings > Account
- Password login returns the existing static token (no auth middleware changes)
- Add account settings: setup, change password, change username, remove password
- Add logout button to sidebar footer
- Add version changelog popup (click version number in sidebar)
- Support all 8 locales (en, zh, de, es, fr, ja, ko, pt)
- Bump version to 0.4.3
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Implement runtime theme switching using CSS custom properties delegated through SCSS variables, with light/dark/system modes, FOUC prevention, sidebar toggle, and settings selector. Add theme-aware video assets for sidebar and chat thinking indicator.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>