feat(ui): Shadow UI redesign, domain management, and DNS autoconfigure (#11119)

Co-authored-by: ShadowArcanist <162910371+ShadowArcanist@users.noreply.github.com>

tests/Feature/ErrorPagesRedesignTest.php

@@ -0,0 +1,71 @@
+<?php
+
+use App\Models\InstanceSettings;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Symfony\Component\HttpKernel\Exception\HttpException;
+
+uses(RefreshDatabase::class);
+
+beforeEach(function () {
+    InstanceSettings::forceCreate(['id' => 0]);
+});
+
+it('renders redesigned error pages with shared shell and actions', function (string $view, string $code, string $title) {
+    $exception = new HttpException((int) $code, 'Test error message');
+
+    $html = view($view, ['exception' => $exception])->render();
+
+    expect($html)
+        ->toContain('error-shell')
+        ->toContain('error-code')
+        ->toContain('error-title')
+        ->toContain('error-actions')
+        ->toContain($code)
+        ->toContain($title)
+        ->toContain('Contact support')
+        ->toContain(config('constants.urls.contact'));
+})->with([
+    '400' => ['errors.400', '400', 'Bad request'],
+    '401' => ['errors.401', '401', 'You shall not pass!'],
+    '402' => ['errors.402', '402', 'Payment required'],
+    '403' => ['errors.403', '403', 'You shall not pass!'],
+    '404' => ['errors.404', '404', 'How did you get here?'],
+    '419' => ['errors.419', '419', 'This page is definitely old, not like you!'],
+    '429' => ['errors.429', '429', 'Woah, slow down there!'],
+    '500' => ['errors.500', '500', 'Wait, this is not cool...'],
+    '503' => ['errors.503', '503', 'We are working on serious things.'],
+]);
+
+it('includes go back and dashboard actions on standard error pages', function () {
+    $exception = new HttpException(404, 'Not found');
+
+    $html = view('errors.404', ['exception' => $exception])->render();
+
+    expect($html)
+        ->toContain('Go back')
+        ->toContain('Dashboard')
+        ->toContain(route('dashboard'));
+});
+
+it('uses login as primary action on session expired page', function () {
+    $exception = new HttpException(419, 'Page expired');
+
+    $html = view('errors.419', ['exception' => $exception])->render();
+
+    expect($html)
+        ->toContain('/login')
+        ->toContain('Back to login')
+        ->toContain('Using a reverse proxy or Cloudflare Tunnel?')
+        ->not->toContain('>Dashboard</');
+});
+
+it('shows purified exception message on 500 page', function () {
+    $exception = new RuntimeException('Database connection failed');
+
+    $html = view('errors.500', ['exception' => $exception])->render();
+
+    expect($html)
+        ->toContain('error-code-danger')
+        ->toContain('error-message')
+        ->toContain('Database connection failed');
+});