fix(security): validate application domains safely

Use shared domain validation and normalization for application, service, and
preview domains so unsafe host input is rejected consistently.

Cover command-substitution payloads in application domain tests.

app/Livewire/Project/Application/PreviewsCompose.php

@@ -3,6 +3,7 @@
 namespace App\Livewire\Project\Application;
 
 use App\Models\ApplicationPreview;
+use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Livewire\Component;
 use Spatie\Url\Url;
@@ -33,6 +34,11 @@ class PreviewsCompose extends Component
     {
         try {
             $this->authorize('update', $this->preview->application);
+            $this->validate([
+                'domain' => ValidationPatterns::applicationDomainRules(),
+            ]);
+
+            $this->domain = ValidationPatterns::normalizeApplicationDomains($this->domain);
 
             $docker_compose_domains = data_get($this->preview, 'docker_compose_domains');
             $docker_compose_domains = json_decode($docker_compose_domains, true) ?: [];
@@ -73,9 +79,13 @@ class PreviewsCompose extends Component
                 $preview_fqdn = str_replace('{{pr_id}}', $this->preview->pull_request_id, $preview_fqdn);
                 $preview_fqdn = str($generated_fqdn)->before('://').'://'.$preview_fqdn;
             } else {
+                foreach (ValidationPatterns::validateApplicationDomains($domain_string) as $error) {
+                    throw new \InvalidArgumentException($error);
+                }
+
                 // Use the existing domain from the main application
                 // Handle multiple domains separated by commas
-                $domain_list = explode(',', $domain_string);
+                $domain_list = ValidationPatterns::applicationDomainList($domain_string);
                 $preview_fqdns = [];
                 $template = $this->preview->application->preview_url_template;
                 $random = new_public_id();