chore(image-updater): use Git write-back for all apps

Set write-back-method=git with write-back-target to this repo, branch=master, and commit identity. Keeps image-list and strategies.\n\nCommitted via Codex CLI.

applications/plex.yaml

@@ -8,8 +8,9 @@ metadata:
     argocd-image-updater.argoproj.io/image-list: plex=linuxserver/plex:latest
     # Use digest strategy to track latest tag updates
     argocd-image-updater.argoproj.io/plex.update-strategy: digest
-    # Write changes back to Git repository (GitOps workflow)
+    # Write back to Git repository (commits to this repo)
     argocd-image-updater.argoproj.io/write-back-method: git
+    argocd-image-updater.argoproj.io/write-back-target: http://gitea-http.gitea.svc.cluster.local:3000/admin/turingpi.git
     # Git configuration for write-back
     argocd-image-updater.argoproj.io/git-branch: master
     argocd-image-updater.argoproj.io/git-commit-user: argocd-image-updater
@@ -38,4 +39,4 @@ spec:
       selfHeal: true
     syncOptions:
     - CreateNamespace=true
-    - ServerSideApply=true
+    - ServerSideApply=true