Switch PHP views to Twig and add 2FA/UI enhancements

Migrate many view templates from raw PHP to Twig and modernize UI/UX for 2FA and settings. Controllers updated to provide avatar data and two-factor info (ProfileController, UserController) and SettingsController now includes timezone lists, notification preset selection, cron path, cached update state and rollback availability. ErrorHandler now attempts to render error pages via a new Core\TwigService with a safe fallback to raw PHP views. TwoFactorService generation silences deprecated warnings during QR code creation. Numerous .php view files were removed and replaced with .twig equivalents (2fa setup/verify/backup-codes and many auth, dashboard, domains, errors, layout, users, tags, tld-registry, etc.), and core/TwigService was added. These changes move the app toward a Twig-based templating system, improve 2FA flows, surface avatar images in lists/profiles, and make error rendering more robust.

core/Controller.php

@@ -6,6 +6,15 @@ abstract class Controller
 {
     protected function view(string $view, array $data = []): void
     {
+        $twigPath = __DIR__ . "/../app/Views/$view.twig";
+
+        if (file_exists($twigPath)) {
+            $twig = TwigService::getInstance();
+            echo $twig->render("$view.twig", $data);
+            return;
+        }
+
+        // Fallback to legacy PHP view during migration
         extract($data);
         $viewPath = __DIR__ . "/../app/Views/$view.php";
 
@@ -13,7 +22,7 @@ abstract class Controller
             throw new \Exception("View not found: $view");
         }
 
-        require_once $viewPath;
+        require $viewPath;
     }
 
     protected function json($data, int $status = 200): void