fix: show access denied page for permission failures

app/Config/Auth.php

@@ -78,8 +78,8 @@ class Auth extends ShieldAuth
         'login'             => '/',
         'logout'            => 'login',
         'force_reset'       => '/',
-        'permission_denied' => '/',
-        'group_denied'      => '/',
+        'permission_denied' => 'access-denied',
+        'group_denied'      => 'access-denied',
     ];
 
     /**

app/Config/Routes.php

@@ -6,6 +6,7 @@ use CodeIgniter\Router\RouteCollection;
  * @var RouteCollection $routes
  */
 $routes->get('/', 'Home::index');
+$routes->get('access-denied', 'Home::accessDenied');
 $routes->get('dashboard', 'Home::dashboard');
 $routes->get('dashboard/opd', 'Home::opdDashboard');
 $routes->get('dashboard/ipd', 'Home::ipdDashboard');

app/Controllers/Home.php

@@ -34,6 +34,18 @@ class Home extends BaseController
         ]);
     }
 
+    public function accessDenied()
+    {
+        $authRedirect = $this->ensureAuthenticated();
+        if ($authRedirect !== null) {
+            return $authRedirect;
+        }
+
+        return $this->response
+            ->setStatusCode(403)
+            ->setBody(view('errors/html/access_denied'));
+    }
+
     public function billing()
     {
         $authRedirect = $this->ensureAuthenticated();

app/Views/errors/html/access_denied.php

@@ -0,0 +1,53 @@
+<!doctype html>
+<html lang="en">
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <title>Access denied</title>
+    <style>
+        :root {
+            color-scheme: light;
+            font-family: "Segoe UI", sans-serif;
+            background: #f4f6f8;
+            color: #17212b;
+        }
+        body {
+            min-height: 100vh;
+            margin: 0;
+            display: grid;
+            place-items: center;
+        }
+        main {
+            width: min(560px, calc(100% - 40px));
+            border-left: 5px solid #b42318;
+            background: #fff;
+            padding: 32px;
+            box-shadow: 0 8px 28px rgba(23, 33, 43, 0.12);
+        }
+        h1 {
+            margin: 0 0 12px;
+            font-size: 28px;
+        }
+        p {
+            margin: 0 0 24px;
+            line-height: 1.55;
+            color: #475467;
+        }
+        a {
+            display: inline-block;
+            color: #fff;
+            background: #175cd3;
+            padding: 10px 16px;
+            text-decoration: none;
+            font-weight: 600;
+        }
+    </style>
+</head>
+<body>
+    <main>
+        <h1>Access denied</h1>
+        <p>Your account does not have the permission required to open this page. Ask an administrator to verify your assigned role and its permissions.</p>
+        <a href="<?= esc(base_url('/')) ?>">Return to HMS</a>
+    </main>
+</body>
+</html>