feat: Provisionner automatiquement un nouvel établissement

Lorsqu'un super-admin crée un établissement via l'interface, le système
doit automatiquement créer la base tenant, exécuter les migrations,
créer le premier utilisateur admin et envoyer l'invitation — le tout
de manière asynchrone pour ne pas bloquer la réponse HTTP.

Ce mécanisme rend chaque établissement opérationnel dès sa création
sans intervention manuelle sur l'infrastructure.

backend/tests/Unit/SuperAdmin/Domain/Model/Establishment/EstablishmentTest.php

@@ -23,11 +23,11 @@ final class EstablishmentTest extends TestCase
     private const string SUBDOMAIN = 'ecole-alpha';
 
     #[Test]
-    public function creerCreatesActiveEstablishment(): void
+    public function creerCreatesProvisioningEstablishment(): void
     {
         $establishment = $this->createEstablishment();
 
-        self::assertSame(EstablishmentStatus::ACTIF, $establishment->status);
+        self::assertSame(EstablishmentStatus::PROVISIONING, $establishment->status);
         self::assertSame(self::ESTABLISHMENT_NAME, $establishment->name);
         self::assertSame(self::SUBDOMAIN, $establishment->subdomain);
         self::assertNull($establishment->lastActivityAt);
@@ -59,10 +59,21 @@ final class EstablishmentTest extends TestCase
         self::assertStringStartsWith('classeo_tenant_', $establishment->databaseName);
     }
 
+    #[Test]
+    public function activerChangesStatusToActif(): void
+    {
+        $establishment = $this->createEstablishment();
+
+        self::assertSame(EstablishmentStatus::PROVISIONING, $establishment->status);
+        $establishment->activer();
+        self::assertSame(EstablishmentStatus::ACTIF, $establishment->status);
+    }
+
     #[Test]
     public function desactiverChangesStatusToInactif(): void
     {
         $establishment = $this->createEstablishment();
+        $establishment->activer();
 
         $establishment->desactiver(new DateTimeImmutable('2026-02-16 12:00:00'));
 
@@ -73,6 +84,7 @@ final class EstablishmentTest extends TestCase
     public function desactiverRecordsEtablissementDesactiveEvent(): void
     {
         $establishment = $this->createEstablishment();
+        $establishment->activer();
         $establishment->pullDomainEvents(); // Clear creation event
 
         $establishment->desactiver(new DateTimeImmutable('2026-02-16 12:00:00'));
@@ -86,6 +98,7 @@ final class EstablishmentTest extends TestCase
     public function desactiverThrowsWhenAlreadyInactive(): void
     {
         $establishment = $this->createEstablishment();
+        $establishment->activer();
         $establishment->desactiver(new DateTimeImmutable('2026-02-16 12:00:00'));
 
         $this->expectException(EstablishmentDejaInactifException::class);
@@ -141,6 +154,7 @@ final class EstablishmentTest extends TestCase
         return Establishment::creer(
             name: self::ESTABLISHMENT_NAME,
             subdomain: self::SUBDOMAIN,
+            adminEmail: 'admin@ecole-alpha.fr',
             createdBy: SuperAdminId::fromString(self::SUPER_ADMIN_ID),
             createdAt: new DateTimeImmutable('2026-02-16 10:00:00'),
         );