Fornax: COORDINATOR_URL env, port-lease webhook, Grafana dashboard

- Worker deployment: add COORDINATOR_URL and WORKER_ID env vars to
  portforward-helper; webhook calls coordinator /api/v2/workers/:id/port-lease
  after each NAT-PMP renewal so coordinator tracks current forwarded port
- Worker overlays: patch WORKER_ID env var to actual worker ID (tx253/tx34)
- Grafana: fornax-grafana Argo CD app pointing to k8s/fornax/grafana/
  ConfigMap with grafana_dashboard=1 label for auto-discovery by sidecar;
  7 panels covering bandwidth, active torrents, worker health, request rate,
  and error rate

servers/legion/k8s/fornax/worker/base/deployment.yaml

@@ -96,12 +96,18 @@ spec:
         - name: portforward-helper
           image: alpine:latest
           imagePullPolicy: Always
+          env:
+            - name: COORDINATOR_URL
+              value: "https://fornax.neuralplatform.ai"
+            - name: WORKER_ID
+              value: "WORKER_ID"
           command:
             - sh
             - -c
             - |
               until apk add -q curl 2>/dev/null; do sleep 5; done
               echo "Watching /tmp/gluetun/forwarded_port for assigned port..."
+              TTL=300
               while true; do
                 if [ -f /tmp/gluetun/forwarded_port ]; then
                   PORT=$(cat /tmp/gluetun/forwarded_port)
@@ -112,6 +118,13 @@ spec:
                     curl -s -b /tmp/qbt.txt -X POST http://localhost:8080/api/v2/app/setPreferences \
                       -d "json={\"listen_port\":$PORT,\"random_port\":false}" >/dev/null 2>&1
                     echo "$(date): qBittorrent listen port set to $PORT"
+                    # Notify coordinator of port lease
+                    if [ -n "$COORDINATOR_URL" ] && [ -n "$WORKER_ID" ]; then
+                      curl -s -X POST "$COORDINATOR_URL/api/v2/workers/$WORKER_ID/port-lease" \
+                        -H "Content-Type: application/json" \
+                        -d "{\"port\": $PORT, \"ttlSeconds\": $TTL}" >/dev/null 2>&1 || true
+                      echo "$(date): Coordinator notified of port $PORT (TTL: ${TTL}s)"
+                    fi
                   else
                     echo "$(date): Port file empty, waiting..."
                   fi