feat: add GitHub repository dashboard with Prometheus metrics

ghtracker authenticates as a GitHub App and scans a configured list of repositories on a schedule. It serves a dashboard, a JSON state endpoint, a health probe and Prometheus metrics.

The dashboard lists only items that need attention: failing workflows, pull requests that wait too long or fail their checks, stale issues and projects that failed to scan. It has search, dynamic filters and a button that rescans on demand. The Vue app is embedded in the Go binary.

The client protects the GitHub rate limit with conditional requests, a request reserve and Retry-After handling.

deploy/kubernetes/ingressroute.yaml

@@ -0,0 +1,16 @@
+# Replace the host. The dashboard has no authentication: keep it on an internal entrypoint
+# or add a Traefik auth middleware before exposing it.
+apiVersion: traefik.io/v1alpha1
+kind: IngressRoute
+metadata:
+  name: ghtracker
+spec:
+  entryPoints:
+    - websecure
+  routes:
+    - match: Host(`ghtracker.example.com`)
+      kind: Rule
+      services:
+        - name: ghtracker
+          port: 80
+  tls: {}