Fix admin content tab retention on test mail & save, add SMTP encryption support, and provide Gmail DNS deliverability diagnostic guidance

tests/Feature/AdminContentTest.php

@@ -10,6 +10,7 @@ use App\Models\User;
 use App\Services\PriceCalculatorService;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Http\UploadedFile;
+use Illuminate\Support\Facades\Mail;
 use Illuminate\Support\Facades\Storage;
 use Tests\TestCase;
 
@@ -407,4 +408,27 @@ class AdminContentTest extends TestCase
         $this->assertEquals(45, (int) Setting::get('calc_default_markup'));
         $this->assertEquals(8, (int) Setting::get('calc_failure_rate'));
     }
+
+    public function test_sending_test_mail_redirects_and_stays_on_email_tab(): void
+    {
+        Mail::fake();
+
+        $response = $this->actingAs($this->admin)->post(route('admin.content.test-mail'), [
+            'test_email' => 'niek.rabelink@gmail.com',
+        ]);
+
+        $response->assertRedirect(route('admin.content.index', ['tab' => 'email']));
+        $response->assertSessionHas('success');
+    }
+
+    public function test_updating_content_with_active_tab_preserves_tab(): void
+    {
+        $response = $this->actingAs($this->admin)->post(route('admin.content.update'), [
+            'active_tab' => 'calculator',
+            'site_name' => 'Jouwdriedee 3D Print Studio',
+        ]);
+
+        $response->assertRedirect(route('admin.content.index', ['tab' => 'calculator']));
+        $response->assertSessionHas('success');
+    }
 }