bdc91177e2
Adds a "Live Monitoring (keepalive)" card listing each SLMM device with its
monitor_enabled state and an Enable/Disable toggle. Reads from /api/slmm/roster
(now includes monitor_enabled) and POSTs to /api/slmm/{unit}/monitor/{start,stop},
which persist the flag in SLMM (survives restarts; auto-started on boot). Shows a
reachability dot + 24/7 ON/OFF badge.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>