ajoute les alertes Prometheus du self-healing et installe Larastan (dette de l'étape 8, 72 erreurs corrigées à la racine)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

portail/app/Services/OpenStack/HeatClient.php

@@ -2,6 +2,7 @@
 
 namespace App\Services\OpenStack;
 
+use Illuminate\Http\Client\PendingRequest;
 use Illuminate\Support\Facades\Http;
 use RuntimeException;
 
@@ -15,6 +16,7 @@ class HeatClient
     public function __construct(private readonly KeystoneAuth $auth) {}
 
     /**
+     * @param  array<string, mixed>  $template
      * @return array{id: string}
      */
     public function creerStack(string $nom, array $template): array
@@ -86,7 +88,7 @@ class HeatClient
         }
     }
 
-    private function requete()
+    private function requete(): PendingRequest
     {
         return Http::withHeaders(['X-Auth-Token' => $this->auth->jeton()]);
     }