feat: rebuild web UI on the shared theta42 app stack; OIDC + local admin auth

The web management UI was a bespoke minimal theme with LDAP-bind login.
Rebuild it to match the SSO Manager and Proxy — same stack, same look/feel,
same auth model. The SSH bridge, audit, metrics, and access logic are
unchanged; this is purely the web layer.

Frontend (mirrors proxy/sso):
- Express + EJS with the shared top.ejs/bottom.ejs shell, Bootstrap 5,
  jQuery, jq-repeat, FontAwesome, Socket.IO, and the shared app-base.js /
  val.js client framework (copied verbatim). Vendor libs served from
  node_modules via /static-modules; app assets via /static.
- Dashboard / Sessions / Audit pages render in the common look/feel,
  loading data through the authenticated /api/* endpoints.

Auth (mirrors proxy):
- OIDC against the SSO (utils/oidc.js + routes/auth.js + models/oidc_state)
  plus a local anti-lockout admin (models/user_redis.js, bootstrapped from
  auth.adminUsers[0] / auth.localAdminPass). AuthToken sessions carry the
  group snapshot; middleware gates the data API on adminGroups or the local
  admin. New config: oidc{} + auth.adminUsers/localAdminPass.
- /api/user/me drives the client login state; "Log in with SSO" hidden when
  oidc.enabled is false.

Verified end to end: local admin login -> token -> /api/user/me isAdmin,
metrics/sessions/audit 200 with token / 401 without / 401 bad password;
static + page shells serve; 26 tests green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

nodejs/models/oidc_state.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const Table = require('.');
+
+/**
+ * OidcState
+ *
+ * Short-lived store for an in-flight OpenID Connect authorization request.
+ * Keyed by the random `state` value; holds the PKCE `code_verifier` and the
+ * post-login redirect target until the SSO calls us back.
+ *
+ * The record auto-expires via model-redis per-key TTL (static _ttl), so an
+ * abandoned login attempt leaves nothing behind and there is no cleanup job.
+ */
+class OidcState extends Table{
+	static _key = 'state';
+
+	// Auth round-trips are quick; 5 minutes is plenty and bounds replay.
+	static _ttl = 300;
+
+	static _keyMap = {
+		'created_on': {default: function(){return (new Date).getTime()}},
+		'state': {isRequired: true, type: 'string', min: 8, max: 500},
+		'codeVerifier': {isRequired: true, type: 'string', min: 8, max: 500},
+		'redirect': {default: '/', isRequired: false, type: 'string'},
+	}
+}
+
+OidcState.register();
+
+module.exports = {OidcState};