refactor: update Vault secret paths to new categorized structure

- argocd: zot → storage/zot, github → platform/github, gitea → platform/gitea
- gitea-runner: gitea → platform/gitea, zot → storage/zot
- tekton: tekton → platform/tekton, zot → storage/zot

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

tekton/ci-cd/manifests/triggers/secret.yaml

@@ -14,5 +14,5 @@ spec:
   data:
     - secretKey: webhook-secret
       remoteRef:
-        key: tekton
+        key: platform/tekton
         property: GITEA_WEBHOOK_SECRET