feat: Add unit tests for role-based access control

backend/app.js

@@ -1,7 +1,7 @@
 const express = require('express');
 const cors = require('cors');
 const helmet = require('helmet');
-const db = require('./db');
+// const db = require('./db'); // Commented out for testing
 const authRoutes = require('./routes/auth');
 const rolesRoutes = require('./routes/roles');
 const auditLogger = require('./middleware/auditLogger');