- New route: #/nodes/:pubkey/analytics with Chart.js v4 visualizations
- Activity timeline (bar), SNR trend (line), packet type breakdown (doughnut)
- Observer coverage (horizontal bar), hop distribution (bar)
- Uptime heatmap (7x24 CSS grid, GitHub-style)
- Peer interactions table with links to node details
- Stat cards: availability, signal grade, packets/day, relay %, silence
- Time range selector: 24h / 7d / 30d / All
- Server: GET /api/nodes/:pubkey/analytics with full aggregation in SQLite
- Analytics button added to both sidebar and full-screen node views