feat(forgejo): Git self-host en miroir de GitHub (git.funklab.online, SSO Authentik) (#96)

- 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-of-apps/apps/forgejo.yaml

@@ -0,0 +1,24 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: forgejo
+  namespace: argocd
+  finalizers:
+    - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+  source:
+    repoURL: git@github.com:Alkatrazz24/Funk-lab.git
+    targetRevision: main
+    path: k8s/apps/forgejo
+    directory:
+      recurse: true
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: ai
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=true