Machine status probe on page load:
- POST /api/machines/refresh probes all machines in parallel (max 20 concurrent, 1.5s timeout)
- Updates DB status and broadcasts via SSE to all connected browser tabs
- Server-side throttle: ignores refresh requests within 10s
- Machines.tsx and Dashboard.tsx fire probe on mount
- Visual "Checking machine status..." indicator in Machines table
- MachineHandler now accepts *Engine for ProbeAllMachines access
Smart WoL: TCP pre-check before sending magic packet (3s timeout).
Machine status updates via SSE: online/offline tracked in DB and
broadcast to all connected browser tabs in real-time.
- Pre-check: if machine already reachable, skip WoL and mark online
- WoL path: send 3 magic packets, wait for SSH, mark online/offline
- Backend: setMachineStatus() helper + machine_status SSE event
- Frontend: subscribeMachineStatus() SSE helper for Machines + Dashboard
- IsReachable() helper in wol package for TCP reachability checks
darroyo