feat: Add role middleware and update permissions documentation

backend/middleware/role.middleware.js

@@ -1,20 +1,23 @@
 /**
  * Middleware to check if the user has the required role(s)
- * @param {string[]} allowedRoles - Array of roles allowed to access the endpoint
+ * @param {string[]} requiredRoles - Array of required roles
  * @returns {function} Express middleware function
  */
-export const requireRole = (allowedRoles) => {
+export const requireRole = (requiredRoles) => {
   return (req, res, next) => {
+    // Get the user's role from the JWT token (assuming it's in req.user.role)
     const userRole = req.user?.role;
 
+    // If no user role is found, deny access
     if (!userRole) {
-      return res.status(401).json({ error: 'Unauthorized: Missing role claim' });
+      return res.status(401).json({ error: 'Unauthorized' });
     }
 
-    if (!allowedRoles.includes(userRole)) {
-      return res.status(403).json({ error: 'Forbidden: Insufficient permissions' });
+    // Check if the user has at least one of the required roles
+    if (requiredRoles.includes(userRole)) {
+      next(); // User has the required role, proceed to the next middleware/route
+    } else {
+      return res.status(403).json({ error: 'Forbidden' });
     }
-    
-    next();
   };
 };