feat(time-tracking) : add ActiveTimeEntryProvider, fixtures, and serialization groups

- ActiveTimeEntryProvider returns active timer for current user
- TimeEntry fixtures with 10 sample entries for the SIRH project
- Add time_entry:read group to Project, User, and TaskType for embedded serialization

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/State/ActiveTimeEntryProvider.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\State;
+
+use ApiPlatform\Metadata\Operation;
+use ApiPlatform\State\ProviderInterface;
+use App\Entity\TimeEntry;
+use App\Repository\TimeEntryRepository;
+use Symfony\Bundle\SecurityBundle\Security;
+
+/**
+ * @implements ProviderInterface<TimeEntry>
+ */
+final readonly class ActiveTimeEntryProvider implements ProviderInterface
+{
+    public function __construct(
+        private Security $security,
+        private TimeEntryRepository $timeEntryRepository,
+    ) {}
+
+    public function provide(Operation $operation, array $uriVariables = [], array $context = []): ?TimeEntry
+    {
+        $user = $this->security->getUser();
+
+        if (!$user) {
+            return null;
+        }
+
+        return $this->timeEntryRepository->findActiveByUser($user);
+    }
+}