feat: add Gitea credentials and Actions runner

- Add gitea-creds ExternalSecret for ArgoCD authentication to Gitea
- Enable Gitea Actions in helm-values.yaml
- Add gitea-runner deployment for CI/CD

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

argocd/image-updater-manifests/image-updater-secret.yaml

@@ -48,3 +48,35 @@ spec:
       remoteRef:
         key: github
         property: password
+---
+apiVersion: external-secrets.io/v1
+kind: ExternalSecret
+metadata:
+  name: gitea-creds
+  namespace: argocd
+spec:
+  refreshInterval: 1h
+  secretStoreRef:
+    kind: ClusterSecretStore
+    name: vault-backend
+  target:
+    name: gitea-creds
+    creationPolicy: Owner
+    template:
+      metadata:
+        labels:
+          argocd.argoproj.io/secret-type: repo-creds
+      data:
+        type: git
+        url: https://github0213.com
+        username: "{{ .username }}"
+        password: "{{ .password }}"
+  data:
+    - secretKey: username
+      remoteRef:
+        key: gitea
+        property: username
+    - secretKey: password
+      remoteRef:
+        key: gitea
+        property: password