Add separate unifi_failure_threshold to avoid false tickets on reboots

UniFi switches/APs take several minutes to rejoin after a firmware-update
reboot (observed AP taking 12 min on the scheduled 3am update), longer than
the 2-consecutive-check (~4 min) threshold shared with host link-down
detection. Give UniFi device offline detection its own, more forgiving
threshold so momentary maintenance reboots don't cut tickets.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UB2D82eYNzD1bnMHhFPjRr

README.md

@@ -148,7 +148,7 @@ returned by the UniFi API for that device.
 
 | Condition | Priority |
 |---|---|
-| UniFi device offline (≥2 consecutive checks) | P2 High |
+| UniFi device offline (≥`unifi_failure_threshold` consecutive checks) | P2 High |
 | Proxmox host NIC link-down regression (≥2 consecutive checks) | P2 High |
 | Host unreachable via ping (≥2 consecutive checks) | P2 High |
 | ≥3 hosts simultaneously reporting interface failures | P1 Critical |
@@ -218,6 +218,7 @@ Shared by both processes. Located in the working directory (`/var/www/html/prod/
   "monitor": {
     "poll_interval": 120,
     "failure_threshold": 2,
+    "unifi_failure_threshold": 5,
     "cluster_threshold": 3,
     "ping_hosts": [
       { "name": "pbs", "ip": "10.10.10.3" }
@@ -243,6 +244,7 @@ Shared by both processes. Located in the working directory (`/var/www/html/prod/
 | `hosts` | Maps Prometheus instance labels → display hostnames |
 | `monitor.poll_interval` | Seconds between full check cycles (default: 120) |
 | `monitor.failure_threshold` | Consecutive failures before creating ticket (default: 2) |
+| `monitor.unifi_failure_threshold` | Consecutive failures before ticketing a UniFi device as offline (default: same as `failure_threshold`). Set higher than `failure_threshold` — UniFi switches/APs can take several minutes to rejoin after a firmware-update reboot, so a low threshold cuts tickets for momentary maintenance reboots instead of real failures. |
 | `monitor.cluster_threshold` | Hosts with failures to trigger cluster-wide P1 (default: 3) |
 | `monitor.ping_hosts` | Hosts checked only by ping (no node_exporter) |