Follow-up to #78:
- Use primaryIp() so href targets the first IP when data.ip is comma-separated (e.g. "192.168.1.1, 2001:db8::1")
- Add primaryIp() helper to maskIp.ts
- Add 4 tests covering single IP link, absent IP, multi-IP href, multi-IP display text
- Add hideIp / toggleHideIp to canvasStore (UI-only, not persisted)
- Add maskIp util: 192.168.1.115 → 192.168.XX.XX (non-IPv4 passthrough)
- BaseNode reads hideIp from store and masks last two octets when active
- Sidebar shows Eye/EyeOff toggle below Scan Network, highlights when active