chore: sync homelab ops, identity, and monitoring docs

monitoring/alerts.yml

@@ -0,0 +1,56 @@
+groups:
+  - name: homelab-core
+    rules:
+      - alert: ScrapeTargetDown
+        expr: up == 0
+        for: 5m
+        labels:
+          severity: warning
+        annotations:
+          summary: "Prometheus target down: {{ $labels.job }}"
+          description: "Target {{ $labels.instance }} for job {{ $labels.job }} has been down for more than 5 minutes."
+
+      - alert: PDMemoryPressureHigh
+        expr: 100 * (1 - (node_memory_MemAvailable_bytes{job="pd-node"} / node_memory_MemTotal_bytes{job="pd-node"})) > 90
+        for: 10m
+        labels:
+          severity: warning
+        annotations:
+          summary: "PD memory usage is high"
+          description: "PlausibleDeniability memory usage has been above 90% for more than 10 minutes."
+
+      - alert: PDFilesystemUsageHigh
+        expr: 100 * (1 - (node_filesystem_avail_bytes{job="pd-node", mountpoint="/", fstype!~"tmpfs|ramfs|overlay|squashfs|nfs4"} / node_filesystem_size_bytes{job="pd-node", mountpoint="/", fstype!~"tmpfs|ramfs|overlay|squashfs|nfs4"})) > 85
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          summary: "PD root filesystem is filling up"
+          description: "PlausibleDeniability root filesystem has been above 85% for more than 15 minutes."
+
+      - alert: PDContainerRecentlyRestarted
+        expr: changes(container_start_time_seconds{job="pd-cadvisor", name!=""}[30m]) > 0
+        for: 5m
+        labels:
+          severity: info
+        annotations:
+          summary: "PD container restarted recently"
+          description: "Container {{ $labels.name }} restarted within the last 30 minutes."
+
+      - alert: PDRestoreVerificationFailed
+        expr: pd_restore_verification_success == 0
+        for: 15m
+        labels:
+          severity: warning
+        annotations:
+          summary: "PD restore verification failed"
+          description: "The last scheduled restore verification on PlausibleDeniability failed."
+
+      - alert: PDRestoreVerificationStale
+        expr: time() - pd_restore_verification_last_success_timestamp_seconds > 8640000
+        for: 1h
+        labels:
+          severity: warning
+        annotations:
+          summary: "PD restore verification is stale"
+          description: "No successful PD restore verification has been recorded in the last 100 days."