fix(07-01): use admin namespace for Gitea repository

- Change repo URL to admin/taskplaner (repo created under admin user)
- Update CI workflow image name to admin/taskplaner
- Update repo secret documentation with correct path

argocd/repo-secret.yaml

@@ -13,7 +13,7 @@
 #     argocd.argoproj.io/secret-type: repository
 # stringData:
 #   type: git
-#   url: http://gitea-http.gitea.svc.cluster.local:3000/tho/taskplaner.git
+#   url: http://gitea-http.gitea.svc.cluster.local:3000/admin/taskplaner.git
 #   username: admin
 #   password: "$PASSWORD"
 # EOF