feat: split Grafana dashboards into per-folder ConfigMaps

Replace monolithic dashboards-configmap.yaml with 10 dedicated files,
one per Grafana folder: Ingress, Observability, Infrastructure, Storage,
Identity, DevTools, Search, Media, La Suite, Communications.

New dashboards for Longhorn, PostgreSQL/CNPG, Cert-Manager, SeaweedFS,
Hydra, Kratos, Gitea, OpenSearch, LiveKit, La Suite golden signals
(Linkerd metrics), Matrix, and Email Pipeline.

base/monitoring/dashboards-media.yaml

@@ -0,0 +1,90 @@
+# Grafana dashboard ConfigMaps — Media
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: grafana-dashboard-livekit
+  namespace: monitoring
+  labels:
+    grafana_dashboard: "1"
+  annotations:
+    grafana_folder: "Media"
+data:
+  livekit.json: |
+    {
+      "annotations": { "list": [] },
+      "editable": true,
+      "panels": [
+        {
+          "title": "Active Rooms",
+          "type": "stat",
+          "gridPos": { "h": 4, "w": 8, "x": 0, "y": 0 },
+          "datasource": { "uid": "prometheus" },
+          "targets": [
+            { "expr": "livekit_room_count", "legendFormat": "rooms" }
+          ]
+        },
+        {
+          "title": "Total Participants",
+          "type": "stat",
+          "gridPos": { "h": 4, "w": 8, "x": 8, "y": 0 },
+          "datasource": { "uid": "prometheus" },
+          "targets": [
+            { "expr": "livekit_participant_count", "legendFormat": "participants" }
+          ]
+        },
+        {
+          "title": "Total Tracks",
+          "type": "stat",
+          "gridPos": { "h": 4, "w": 8, "x": 16, "y": 0 },
+          "datasource": { "uid": "prometheus" },
+          "targets": [
+            { "expr": "livekit_track_count", "legendFormat": "tracks" }
+          ]
+        },
+        {
+          "title": "Packet Rate",
+          "type": "timeseries",
+          "gridPos": { "h": 8, "w": 8, "x": 0, "y": 4 },
+          "datasource": { "uid": "prometheus" },
+          "targets": [
+            {
+              "expr": "sum(rate(livekit_packet_total[5m])) by (direction)",
+              "legendFormat": "{{direction}}"
+            }
+          ],
+          "fieldConfig": { "defaults": { "unit": "ops" } }
+        },
+        {
+          "title": "Bandwidth",
+          "type": "timeseries",
+          "gridPos": { "h": 8, "w": 8, "x": 8, "y": 4 },
+          "datasource": { "uid": "prometheus" },
+          "targets": [
+            {
+              "expr": "sum(rate(livekit_bytes_total[5m])) by (direction)",
+              "legendFormat": "{{direction}}"
+            }
+          ],
+          "fieldConfig": { "defaults": { "unit": "Bps" } }
+        },
+        {
+          "title": "NACK Rate",
+          "type": "timeseries",
+          "gridPos": { "h": 8, "w": 8, "x": 16, "y": 4 },
+          "datasource": { "uid": "prometheus" },
+          "targets": [
+            {
+              "expr": "sum(rate(livekit_nack_total[5m]))",
+              "legendFormat": "NACKs"
+            }
+          ],
+          "fieldConfig": { "defaults": { "unit": "ops" } }
+        }
+      ],
+      "schemaVersion": 39,
+      "tags": ["livekit", "media", "webrtc"],
+      "time": { "from": "now-1h", "to": "now" },
+      "title": "LiveKit",
+      "uid": "livekit"
+    }