feat(monitoring): add mana-geocoding + Pelias to prod compose, Prometheus, Grafana, and status.mana.how

Production deployment + observability for the self-hosted geocoding stack:

**docker-compose.macmini.yml**
- New mana-geocoding container (port 3018, internal-only — no traefik
  labels, no Cloudflare route). Uses host.docker.internal to reach the
  Pelias API on the host's pelias compose stack. Dockerfile added under
  services/mana-geocoding/ using the same Bun/Hono pattern as mana-events.

**Prometheus**
- New blackbox-internal job probing mana-geocoding:3018/health, the
  Pelias API on host.docker.internal:4000/v1/status, and Elasticsearch
  at host.docker.internal:9200/_cluster/health. Kept separate from
  blackbox-api which is reserved for public HTTPS endpoints.

**status.mana.how (generate-status-page.sh)**
- Include blackbox-internal in the metric query and add an "Interne
  Dienste" section with its own summary card, right between Infrastruktur
  and GPU Dienste. Summary grid goes from 4 to 5 columns with a
  900px breakpoint.
- friendly_name() now handles http:// URLs and rewrites container-name
  hosts like mana-geocoding:3018/health → "Mana Geocoding",
  host.docker.internal:4000 → "Pelias API",
  host.docker.internal:9200 → "Pelias Elasticsearch".

**Grafana uptime dashboard**
- Add an "Internal" series to the "Alle Dienste — Uptime-Verlauf" panel
- New "Interne Dienste Status" table panel showing per-instance up/down
- New "Geocoding Ø Latenz" stat panel for probe_duration_seconds

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

docker/prometheus/prometheus.yml

@@ -283,6 +283,27 @@ scrape_configs:
       - target_label: __address__
         replacement: blackbox-exporter:9115
 
+  # Internal-only services (not exposed via Cloudflare).
+  # Probed over the Docker network so the blackbox exporter reaches
+  # them by container name.
+  - job_name: 'blackbox-internal'
+    metrics_path: /probe
+    params:
+      module: [http_2xx]
+    static_configs:
+      - targets:
+          - http://mana-geocoding:3018/health
+          # Pelias stack runs on host network, reached via host gateway
+          - http://host.docker.internal:4000/v1/status
+          - http://host.docker.internal:9200/_cluster/health
+    relabel_configs:
+      - source_labels: [__address__]
+        target_label: __param_target
+      - source_labels: [__param_target]
+        target_label: instance
+      - target_label: __address__
+        replacement: blackbox-exporter:9115
+
   # Infrastructure & Monitoring Tools
   - job_name: 'blackbox-infra'
     metrics_path: /probe