fix: Strict env enforcement, rock-solid Alpine portal rendering, and Nabeh/Redis test diagnostics

backend/public/index.php

@@ -36,7 +36,7 @@ $router->get('/teacher', function ($request, $response) {
     $response->html(\App\Views\TeacherPortal::render());
 });
 
-// Health Check
+// Health & Diagnostic Routes
 $router->get('/api/health', function ($request, $response) {
     $response->json([
         'status'   => 'success',
@@ -45,6 +45,8 @@ $router->get('/api/health', function ($request, $response) {
         'time'     => date('Y-m-d H:i:s')
     ]);
 });
+$router->get('/api/test/nabeh',  [\App\Controllers\TestController::class, 'testNabeh']);
+$router->get('/api/test/system', [\App\Controllers\TestController::class, 'testSystem']);
 
 // OTP Authentication Routes (WhatsApp via Nabeh Gateway + Device Fingerprinting)
 $router->post('/api/auth/otp/request', [\App\Controllers\AuthController::class, 'requestOtp'], [\App\Middlewares\RateLimitMiddleware::class]);