ops: glance borg-backup-widget via prometheus + synthwave/matrix presets

- glance zusaetzlich in monitoring_net (nur lesende Prometheus-Query, kein neuer Listener)
- Borg-Widget: Backup-Alter aus homelab_borg_last_completed_timestamp_seconds, Status aus homelab_borg_last_success
- Theme-Presets synthwave und matrix

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ops/glance/config/home.yml

@@ -455,6 +455,34 @@
           username: ${GLANCE_ADGUARD_USERNAME}
           password: ${GLANCE_ADGUARD_PASSWORD}
 
+        - type: custom-api
+          title: Borg Backup
+          title-url: https://borg.kaleschke.info
+          cache: 15m
+          url: http://monitoring-prometheus:9090/api/v1/query?query=homelab_borg_last_completed_timestamp_seconds
+          subrequests:
+            success:
+              url: http://monitoring-prometheus:9090/api/v1/query?query=homelab_borg_last_success
+          template: |
+            {{ $ts := .JSON.Float "data.result.0.value.1" }}
+            {{ $archive := .JSON.String "data.result.0.metric.archive" }}
+            {{ $succ := .Subrequest "success" }}
+            {{ $ok := $succ.JSON.Float "data.result.0.value.1" }}
+            {{ $status := $succ.JSON.String "data.result.0.metric.status" }}
+            {{ if eq $ts 0.0 }}
+            <div class="text-center color-subdue">Keine Backup-Metrik gefunden</div>
+            {{ else }}
+            {{ $ageHours := div (sub (toFloat now.Unix) $ts) 3600.0 }}
+            <div class="text-center">
+              <div class="size-h2 {{ if gt $ageHours 30.0 }}color-negative{{ else }}color-positive{{ end }}">vor {{ printf "%.0f" $ageHours }} h</div>
+              <div class="size-h6 color-subdue" style="margin-top: 4px;">letztes abgeschlossenes Backup</div>
+              <div class="size-h6 {{ if eq $ok 1.0 }}color-positive{{ else }}color-negative{{ end }}" style="margin-top: 6px;">
+                {{ if eq $ok 1.0 }}letzter Job erfolgreich{{ else }}letzter Job: {{ $status }}{{ end }}
+              </div>
+              {{ if ne $archive "" }}<div class="size-h6 color-subdue text-truncate" style="margin-top: 2px;">{{ $archive }}</div>{{ end }}
+            </div>
+            {{ end }}
+
         - type: group
           widgets:
             - type: docker-containers