feat(forgejo): Git self-host en miroir de GitHub (git.funklab.online, SSO Authentik)

- k8s/apps/forgejo : deployment (image forgejo:11, config par env), service, PVC nfs,
  IngressRoute interne (git.lab.local) + publique (git.funklab.online + middlewares
  security-headers/ratelimit), Application ArgoCD (ns ai, recurse)
- base PostgreSQL `forgejo` sur storage-01 (rôle postgresql)
- vault : vault_pg_forgejo_password + vault_forgejo_oauth_client_secret
- doc admin/k8s/forgejo.md (archi, OIDC, création du miroir, pièges) + index + CLAUDE.md

GitHub reste la source de vérité (pull-mirror lecture seule) — ArgoCD inchangé.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

k8s/apps/forgejo/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: forgejo
+  namespace: ai
+spec:
+  selector:
+    app: forgejo
+  ports:
+    - port: 3000
+      targetPort: 3000