fix(ops): monitor systemd runners in host baseline

apps/api/src/services/proactive_inspector.py

@@ -128,6 +128,20 @@ MONITORED_METRICS: list[dict[str, Any]] = [
         "threshold": 5.0,
         "description": "Docker 容器 15 分鐘重啟增量",
     },
+    {
+        # 2026-05-05 ogt + Codex: 110 runner watchdog loop was invisible to Docker metrics.
+        "name": "systemd_runner_restart_spike_15m",
+        "promql": 'sum(increase(systemd_unit_restarts_total{unit=~"actions\\\\.runner\\\\..*"}[15m])) or on() vector(0)',
+        "threshold": 2.0,
+        "description": "Systemd GitHub/Gitea runner 15 分鐘重啟增量",
+    },
+    {
+        # 2026-05-05 ogt + Codex: GitHub runner service should not use systemd WatchdogSec.
+        "name": "systemd_runner_watchdog_enabled",
+        "promql": 'max(systemd_unit_watchdog_seconds{unit=~"actions\\\\.runner\\\\..*"}) or on() vector(0)',
+        "threshold": 0.0,
+        "description": "Systemd runner WatchdogSec 是否啟用",
+    },
     {
         "name": "pod_restart_rate",
         # kube-state-metrics: namespace=awoooi-prod，sum 聚合避免 multi-vector