- Host cards grid with live status (green/red/yellow badges), latency, expandable details
- Service table with category, URL/port, status, latency
- Local services tab (from ss -tlnp)
- Auto-refresh every 30s with visual countdown bar
- Manual refresh button with rotate animation
- Summary bar (online/degraded/offline/total counts)
- Mobile-responsive: single-column cards, scrollable tables
- Tab-based navigation between Hosts / Services / Local Services
- Added GET /api/config/list - list whitelisted config files with metadata
- Added GET /api/config/read - read file content with line numbers
- Added POST /api/config/save - save with auto-backup and YAML validation
- Added POST /api/config/backup - manual backup endpoint
- Security: whitelist-based path validation, rejects paths outside whitelist
- Auto-backup before save with .bak.<timestamp> naming
- YAML validation for .yaml/.yml files
- Frontend: file list sidebar, code editor with line numbers, status bar
- Mobile-responsive layout (file list top, editor below)
- Config panel in nav, lazy-loaded when navigated to
- 13/13 tests passing
shawn