feat(monitoring): add GlitchTip health check and disk space monitoring

- Add GlitchTip to health-check.sh monitoring endpoints
- Add native disk space checks for / and /Volumes/ManaData with 80%/90% thresholds
- Extend Prometheus disk alerts to include /host_mnt/Volumes/ManaData mountpoint
- Add ManaData disk usage gauge to Grafana system-overview dashboard

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/grafana/dashboards/system-overview.json

@@ -36,7 +36,7 @@
 				},
 				"overrides": []
 			},
-			"gridPos": { "h": 5, "w": 4, "x": 0, "y": 1 },
+			"gridPos": { "h": 5, "w": 3, "x": 0, "y": 1 },
 			"id": 21,
 			"options": {
 				"orientation": "auto",
@@ -79,7 +79,7 @@
 				},
 				"overrides": []
 			},
-			"gridPos": { "h": 5, "w": 4, "x": 4, "y": 1 },
+			"gridPos": { "h": 5, "w": 3, "x": 3, "y": 1 },
 			"id": 22,
 			"options": {
 				"orientation": "auto",
@@ -122,7 +122,7 @@
 				},
 				"overrides": []
 			},
-			"gridPos": { "h": 5, "w": 4, "x": 8, "y": 1 },
+			"gridPos": { "h": 5, "w": 3, "x": 6, "y": 1 },
 			"id": 23,
 			"options": {
 				"orientation": "auto",
@@ -145,6 +145,49 @@
 			"title": "Disk Usage (/)",
 			"type": "gauge"
 		},
+		{
+			"datasource": { "type": "prometheus", "uid": "${datasource}" },
+			"fieldConfig": {
+				"defaults": {
+					"color": { "mode": "thresholds" },
+					"mappings": [],
+					"max": 100,
+					"min": 0,
+					"thresholds": {
+						"mode": "absolute",
+						"steps": [
+							{ "color": "green", "value": null },
+							{ "color": "yellow", "value": 70 },
+							{ "color": "red", "value": 85 }
+						]
+					},
+					"unit": "percent"
+				},
+				"overrides": []
+			},
+			"gridPos": { "h": 5, "w": 3, "x": 9, "y": 1 },
+			"id": 30,
+			"options": {
+				"orientation": "auto",
+				"reduceOptions": {
+					"calcs": ["lastNotNull"],
+					"fields": "",
+					"values": false
+				},
+				"showThresholdLabels": false,
+				"showThresholdMarkers": true
+			},
+			"pluginVersion": "10.0.0",
+			"targets": [
+				{
+					"datasource": { "type": "prometheus", "uid": "${datasource}" },
+					"expr": "100 - ((node_filesystem_avail_bytes{mountpoint=~\"/host_mnt/Volumes/ManaData\"} / node_filesystem_size_bytes{mountpoint=~\"/host_mnt/Volumes/ManaData\"}) * 100)",
+					"refId": "A"
+				}
+			],
+			"title": "Disk Usage (ManaData)",
+			"type": "gauge"
+		},
 		{
 			"datasource": { "type": "prometheus", "uid": "${datasource}" },
 			"fieldConfig": {

docker/prometheus/alerts.yml

@@ -122,8 +122,8 @@ groups:
       # High Disk Usage (> 80%)
       - alert: HighDiskUsage
         expr: |
-          (1 - (node_filesystem_avail_bytes{mountpoint=~"/host_mnt/Users|/"}
+          (1 - (node_filesystem_avail_bytes{mountpoint=~"/host_mnt/Users|/|/host_mnt/Volumes/ManaData"}
-          / node_filesystem_size_bytes{mountpoint=~"/host_mnt/Users|/"})) * 100 > 80
+          / node_filesystem_size_bytes{mountpoint=~"/host_mnt/Users|/|/host_mnt/Volumes/ManaData"})) * 100 > 80
         for: 10m
         labels:
           severity: warning
@@ -134,8 +134,8 @@ groups:
       # Very High Disk Usage (> 90%)
       - alert: VeryHighDiskUsage
         expr: |
-          (1 - (node_filesystem_avail_bytes{mountpoint=~"/host_mnt/Users|/"}
+          (1 - (node_filesystem_avail_bytes{mountpoint=~"/host_mnt/Users|/|/host_mnt/Volumes/ManaData"}
-          / node_filesystem_size_bytes{mountpoint=~"/host_mnt/Users|/"})) * 100 > 90
+          / node_filesystem_size_bytes{mountpoint=~"/host_mnt/Users|/|/host_mnt/Volumes/ManaData"})) * 100 > 90
         for: 5m
         labels:
           severity: critical

scripts/mac-mini/health-check.sh

@@ -273,6 +273,7 @@ echo ""
 echo "Monitoring:"
 check_service "Grafana" "http://localhost:8000/api/health"
 check_service "Umami" "http://localhost:8010/api/heartbeat"
+check_service "GlitchTip" "http://localhost:8020/_health/"
 check_service "VictoriaMetrics" "http://localhost:9090/health"
 
 echo ""
@@ -281,6 +282,36 @@ check_service "vmalert" "http://localhost:8880/health"
 check_service "Alertmanager" "http://localhost:9093/-/healthy"
 check_service "Alert Notifier" "http://localhost:9095/health"
 
+echo ""
+echo "Disk Space:"
+check_disk() {
+    local name=$1
+    local path=$2
+    local warn_pct=${3:-80}
+    local crit_pct=${4:-90}
+
+    if [ ! -d "$path" ]; then
+        echo -e "  ${YELLOW}[SKIP]${NC} $name ($path not found)"
+        return 0
+    fi
+
+    local usage_pct=$(df "$path" | tail -1 | awk '{gsub(/%/,""); print $5}')
+    local avail=$(df -h "$path" | tail -1 | awk '{print $4}')
+
+    if [ "$usage_pct" -ge "$crit_pct" ]; then
+        echo -e "  ${RED}[CRIT]${NC} $name: ${usage_pct}% used ($avail free)"
+        FAILURES+=("Disk $name: ${usage_pct}% (critical)")
+    elif [ "$usage_pct" -ge "$warn_pct" ]; then
+        echo -e "  ${YELLOW}[WARN]${NC} $name: ${usage_pct}% used ($avail free)"
+        FAILURES+=("Disk $name: ${usage_pct}% (warning)")
+    else
+        echo -e "  ${GREEN}[OK]${NC} $name: ${usage_pct}% used ($avail free)"
+    fi
+}
+
+check_disk "System (/)" "/"
+check_disk "ManaData" "/Volumes/ManaData"
+
 echo ""
 echo "Cloudflare Tunnel:"
 if pgrep -x "cloudflared" >/dev/null; then