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/Scolarite/Application/Query/GetStudentProgression/GetStudentProgressionHandlerTest.php

@@ -0,0 +1,78 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Scolarite\Application\Query\GetStudentProgression;
+
+use App\Scolarite\Application\Query\GetStudentProgression\GetStudentProgressionHandler;
+use App\Scolarite\Application\Query\GetStudentProgression\GetStudentProgressionQuery;
+use App\Scolarite\Domain\Service\TeacherStatisticsCalculator;
+use App\Scolarite\Infrastructure\ReadModel\InMemoryTeacherStatisticsReader;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+
+final class GetStudentProgressionHandlerTest extends TestCase
+{
+    private InMemoryTeacherStatisticsReader $reader;
+    private GetStudentProgressionHandler $handler;
+
+    protected function setUp(): void
+    {
+        $this->reader = new InMemoryTeacherStatisticsReader();
+        $this->handler = new GetStudentProgressionHandler(
+            $this->reader,
+            new TeacherStatisticsCalculator(),
+        );
+    }
+
+    #[Test]
+    public function itReturnsEmptyProgressionWhenNoGrades(): void
+    {
+        $result = ($this->handler)($this->query());
+
+        self::assertSame([], $result->grades);
+        self::assertNull($result->trendLine);
+    }
+
+    #[Test]
+    public function itReturnsSingleGradeWithNoTrendLine(): void
+    {
+        $this->reader->feedGradeHistory([
+            ['date' => '2026-01-15', 'value' => 12.0, 'evaluationTitle' => 'Contrôle 1'],
+        ]);
+
+        $result = ($this->handler)($this->query());
+
+        self::assertCount(1, $result->grades);
+        self::assertSame('2026-01-15', $result->grades[0]->date);
+        self::assertSame(12.0, $result->grades[0]->value);
+        self::assertNull($result->trendLine);
+    }
+
+    #[Test]
+    public function itComputesTrendLineFromMultipleGrades(): void
+    {
+        $this->reader->feedGradeHistory([
+            ['date' => '2026-01-15', 'value' => 10.0, 'evaluationTitle' => 'Contrôle 1'],
+            ['date' => '2026-02-10', 'value' => 12.0, 'evaluationTitle' => 'Contrôle 2'],
+            ['date' => '2026-03-05', 'value' => 14.0, 'evaluationTitle' => 'Contrôle 3'],
+        ]);
+
+        $result = ($this->handler)($this->query());
+
+        self::assertCount(3, $result->grades);
+        self::assertNotNull($result->trendLine);
+        self::assertGreaterThan(0, $result->trendLine->slope); // Positive trend
+    }
+
+    private function query(): GetStudentProgressionQuery
+    {
+        return new GetStudentProgressionQuery(
+            studentId: '550e8400-e29b-41d4-a716-446655440050',
+            subjectId: '550e8400-e29b-41d4-a716-446655440030',
+            classId: '550e8400-e29b-41d4-a716-446655440020',
+            teacherId: '550e8400-e29b-41d4-a716-446655440010',
+            tenantId: '550e8400-e29b-41d4-a716-446655440001',
+        );
+    }
+}