v1.16.0: OpenBao as central secrets store + vault broker + UI rework

- Boot: bao-conf.init('sso-manager') replaces conf_manager; deep-merges
  secret/sso-manager/conf over file config (fail-soft). Scoped VAULT_TOKEN
  (policy sso-broker), never root.
- /api/vault reworked: middleware.auth -> scopeGuard -> token-injecting
  proxy. vault_broker.js mints Redis-cached per-user (user-<uid>) /
  per-admin (sso-admin) tokens via the sso-broker role; scopeGuard enforces
  path prefix on top of the OpenBao policy. Client auth-token stripped.
- vault UI renamed (vaultwarden.ejs -> vault.ejs), /vault route auth-gated,
  role-scoped: users see only secret/users/<uid>/, admins get free-form +
  Apps mint tab (secret/apps/<name>/*, token shown once).
- api_conf.js writes via bao-conf.set('sso-manager', ...).
- Remediation: config/*-secrets.js untracked+gitignored, test_plugins.js
  deleted, proxy-secrets.js.example placeholder added. Secrets remain in
  git history; provider-side rotation is the real fix.

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

nodejs/bin/www

@@ -31,7 +31,12 @@ const models = require('../models');
  * Initialize ORM, then Listen on provided port, on all network interfaces.
  */
 models.initORM().then(() => {
-  return require('../utils/conf_manager').init();
+  // Overlay secret/sso-manager/conf from OpenBao over the file-loaded conf.
+  // Fail-soft: if OpenBao is unreachable, conf keeps the ./config/sso-secrets.js
+  // values and boot continues. (Same position the old conf_manager held, so
+  // call-time conf readers — which is how sso consumes its secrets — are
+  // unaffected; nothing in sso captures a secret at require time.)
+  return require('@simpleworkjs/bao-conf').init({ path: 'sso-manager', conf });
 }).then(() => {
   server.listen(port);
   server.on('error', onError);