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/auth.js

@@ -0,0 +1,118 @@
+'use strict';
+
+const Table = require('../models');
+const {User, AuthToken} = Table.models;
+
+/**
+ * Auth Model
+ *
+ * Handles authentication operations for the application.
+ * Manages user login, token validation, and logout processes.
+ *
+ * Dependencies:
+ * - User model: Validates user credentials
+ * - AuthToken model: Creates and manages authentication tokens
+ *
+ * All methods throw standardized login errors on failure to avoid
+ * leaking information about whether usernames exist or tokens are valid.
+ */
+class Auth{
+	/**
+	 * Standardized error responses for authentication failures.
+	 * Returns generic "Invalid Credentials" message for security.
+	 */
+	static errors = {
+		login: function(){
+			let error = new Error('LoginFailed');
+			error.name = 'LoginFailed';
+			error.message = `Invalid Credentials, login failed.`;
+			error.status = 401;
+
+			return error;
+		}
+	}
+
+	/**
+	 * Authenticate user and create session token.
+	 *
+	 * @param {Object} data - Login credentials {username, password}
+	 * @returns {Object} {user, token} - User object and auth token
+	 * @throws {Error} Generic login error on any failure
+	 *
+	 * Flow:
+	 * 1. Validate credentials via User.login()
+	 * 2. Create new AuthToken for the user
+	 * 3. Return both user data and token
+	 */
+	static async login(data){
+		try{
+			let user = await User.login(data);
+			// Backends may attach group membership to the user (LDAP); default
+			// to none for local/redis users.
+			let groups = Array.isArray(user.groups) ? user.groups : [];
+			let token = await AuthToken.create({username: user.username, groups});
+
+			return {user, token}
+		}catch(error){
+			console.log('login error', error);
+			throw this.errors.login();
+		}
+	}
+
+	/**
+	 * Establish a session for an OIDC-authenticated identity: JIT-provision the
+	 * local user (redis-backed) and mint an AuthToken carrying the SSO groups.
+	 *
+	 * @param {Object} identity - {username, groups} from utils/oidc claims
+	 * @returns {Object} {user, token}
+	 */
+	static async oidcSession(identity){
+		let user = typeof User.upsertOidc === 'function'
+			? await User.upsertOidc(identity)
+			: await User.get(identity.username);
+		let token = await AuthToken.create({
+			username: user.username,
+			groups: identity.groups || [],
+		});
+
+		return {user, token};
+	}
+
+	/**
+	 * Validate an authentication token.
+	 *
+	 * @param {string} token - Token string to validate
+	 * @returns {Object} Token object if valid
+	 * @throws {Error} Generic login error if token invalid or expired
+	 *
+	 * Checks:
+	 * 1. Token exists in database
+	 * 2. Token has not expired (via token.check())
+	 */
+	static async checkToken(token){
+		try{
+			token = await AuthToken.get(token);
+			if(token && token.check()) return token;
+
+			throw this.errors.login();
+		}catch(error){
+			console.log('check error', error);
+			throw this.errors.login();
+		}
+	}
+
+	/**
+	 * Destroy an authentication token (logout).
+	 *
+	 * @param {string} data - Token string to destroy
+	 * @returns {void}
+	 *
+	 * Removes token from database, invalidating the session.
+	 */
+	static async logout(data){
+		let token = await AuthToken.get(data);
+		await token.destroy();
+	}
+}
+
+module.exports = {Auth};