feat(absences) : outils MCP CRUD pour les absences

Expose le module Absences via le serveur MCP et comble les trous CRUD
existants (projets, groupes, métadonnées de tâches, clients, users RH).

Absences (réutilise AbsenceDayCalculator + AbsenceBalanceService pour ne
pas contourner la logique de soldes) :
- list/get/create/review/cancel/delete-absence-request
- list/update-absence-policy, list/update-absence-balance
- create-absence-request prend un userId explicite (agir au nom d'un employé) ;
  review/cancel maintiennent les soldes (pending/taken) cohérents
- AbsenceRequestRepository::findFiltered pour les filtres de liste

Trous CRUD comblés :
- delete-project, delete-group
- CRUD tag, effort, priority
- CRUD status (couplé au workflow, avec category)
- CRUD client, get/update-user (champs RH, sans password ni roles)

Sérialisation centralisée (Serializer::absenceRequest/Policy/Balance/client/userFull).
Instructions MCP (mcp.yaml) mises à jour : statuts par workflow + domaine absences.

Tests : tests/Functional/Mcp/AbsenceRequestLifecycleTest (création / approbation /
annulation admin) vérifient le cycle complet et la cohérence des soldes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Mcp/Tool/Reference/GetUserTool.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Mcp\Tool\Reference;
+
+use App\Mcp\Tool\Serializer;
+use App\Repository\UserRepository;
+use InvalidArgumentException;
+use Mcp\Capability\Attribute\McpTool;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\Security\Core\Exception\AccessDeniedException;
+
+use function sprintf;
+
+#[McpTool(name: 'get-user', description: 'Get a user by ID with full HR profile (employee flag, hire/end date, contract, work-time ratio, leave entitlement, reference period, family situation).')]
+class GetUserTool
+{
+    public function __construct(
+        private readonly UserRepository $userRepository,
+        private readonly Security $security,
+    ) {}
+
+    public function __invoke(int $id): string
+    {
+        if (!$this->security->isGranted('ROLE_ADMIN')) {
+            throw new AccessDeniedException('Access denied: ROLE_ADMIN required.');
+        }
+
+        $user = $this->userRepository->find($id);
+        if (null === $user) {
+            throw new InvalidArgumentException(sprintf('User with ID %d not found.', $id));
+        }
+
+        return json_encode(Serializer::userFull($user));
+    }
+}