Add settings nav tree, Logs viewer, and About page (Voicebox-style hierarchy)
- Sidebar: Settings → nav-tree-head with sub-items (General, Connections,
Playback, Payloads, Storage, API Keys, Backup, Logs, About)
- nav.js: navSettingsCat() scrolls to section, expands tree on activate
- General: theme select synced with applyTheme, surfaces dark/light toggle
- Logs: /api/logs endpoint (300-entry circular buffer), refresh/clear/
auto-refresh every 3 s, level filters (All/Error/Warning/Info)
- About: backend availability chips from _ttsBackends, tech stack tags
- server.py: _BufferHandler attaches to root logger, /api/logs GET+DELETE
- Fix duplicate toast on save, guard removed settings-btn reference
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
mARTin-B78
cd770801dc