fix: agent REST router mounted before 404; promote opens pre-filled modal; Directory refresh; Vault OpenBao (v1.28.0) (#169)

- api_agent: REST router mounted synchronously in app.js (was post-listen, behind
  the 404 catch-all -> /api/agent/* 404'd); WS init stays on onListen
- directory.ejs: promote opens a pre-filled resource modal (Save confirms);
  addEdge/removeEdge call loadResources() (was undefined loadData -> stale table);
  addGroup/removeGroup refresh the Access column
- vault.ejs: 'Powered by OpenBao' header badge

nodejs/package.json

@@ -1,6 +1,6 @@
 {
   "name": "t42-sso-manager",
-  "version": "1.27.0",
+  "version": "1.28.0",
   "description": "A very simple LDAP management and SSO system",
   "author": [
     {