feat(absences) : fondation backend du module de gestion des absences

Module type Payfit (étapes 1+2 de la spec V1) : demande d'absence, validation
admin, soldes à jour.

- Enums : AbsenceType, AbsenceStatus, HalfDay, ContractType, FamilySituation
- Entités : AbsencePolicy, AbsenceBalance, AbsenceRequest + champs RH sur User
- Services : PublicHolidayProvider (fériés FR métropole en PHP pur, Computus),
  AbsenceDayCalculator (décompte jours ouvrés/ouvrables + demi-journées, TDD),
  AbsenceBalanceService (périodes + pending/taken/recrédit)
- API Platform : providers/processors (création, approve/reject/cancel) + RBAC
  me/admin, contrôleurs preview (dry-run), upload/download justificatif, calendrier
- Migrations : une par table + colonnes RH user (DEFAULT puis DROP DEFAULT)
- Fixtures : 5 policies par défaut, salariés démo, soldes et demandes
- Tests unitaires : PublicHolidayProvider, AbsenceDayCalculator (12 tests)

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

src/Service/AbsenceBalanceService.php

@@ -0,0 +1,122 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Service;
+
+use App\Entity\AbsenceBalance;
+use App\Entity\AbsenceRequest;
+use App\Entity\User;
+use App\Enum\AbsenceType;
+use App\Repository\AbsenceBalanceRepository;
+use DateTimeInterface;
+use Doctrine\ORM\EntityManagerInterface;
+
+/**
+ * Maintains per-employee leave balances as absence requests move through their
+ * lifecycle: a PENDING request reserves days in `pending`, an APPROVED one
+ * moves them to `taken`, and a cancellation gives them back.
+ */
+final readonly class AbsenceBalanceService
+{
+    public function __construct(
+        private EntityManagerInterface $entityManager,
+        private AbsenceBalanceRepository $balanceRepository,
+    ) {}
+
+    /**
+     * Reference period string for a request: paid leave follows the employee's
+     * reference period (e.g. "2025-2026"), other types are tracked yearly.
+     */
+    public function periodFor(User $user, AbsenceType $type, DateTimeInterface $date): string
+    {
+        if (AbsenceType::PaidLeave !== $type) {
+            return $date->format('Y');
+        }
+
+        $year            = (int) $date->format('Y');
+        $startMonthDay   = $user->getReferencePeriodStart(); // e.g. "06-01"
+        $currentMonthDay = $date->format('m-d');
+
+        $startYear = $currentMonthDay >= $startMonthDay ? $year : $year - 1;
+
+        return sprintf('%d-%d', $startYear, $startYear + 1);
+    }
+
+    public function getOrCreateBalance(User $user, AbsenceType $type, string $period): AbsenceBalance
+    {
+        $balance = $this->balanceRepository->findOneForPeriod($user, $type, $period);
+
+        if (null === $balance) {
+            $balance = new AbsenceBalance()
+                ->setUser($user)
+                ->setType($type)
+                ->setPeriod($period)
+            ;
+            $this->entityManager->persist($balance);
+        }
+
+        return $balance;
+    }
+
+    /** Reserve the requested days in the PENDING bucket. */
+    public function reservePending(AbsenceRequest $request): void
+    {
+        if (!$this->shouldTrack($request)) {
+            return;
+        }
+
+        $balance = $this->balanceForRequest($request);
+        $balance->setPending($balance->getPending() + $request->getCountedDays());
+    }
+
+    /** Move reserved days from PENDING to TAKEN on approval. */
+    public function applyApproval(AbsenceRequest $request): void
+    {
+        if (!$this->shouldTrack($request)) {
+            return;
+        }
+
+        $balance = $this->balanceForRequest($request);
+        $balance->setPending(max(0.0, $balance->getPending() - $request->getCountedDays()));
+        $balance->setTaken($balance->getTaken() + $request->getCountedDays());
+    }
+
+    /**
+     * Give days back when a request is cancelled or rejected.
+     *
+     * @param bool $wasApproved true if the request had already been approved
+     *                          (days were in TAKEN), false if still PENDING
+     */
+    public function release(AbsenceRequest $request, bool $wasApproved): void
+    {
+        if (!$this->shouldTrack($request)) {
+            return;
+        }
+
+        $balance = $this->balanceForRequest($request);
+
+        if ($wasApproved) {
+            $balance->setTaken(max(0.0, $balance->getTaken() - $request->getCountedDays()));
+        } else {
+            $balance->setPending(max(0.0, $balance->getPending() - $request->getCountedDays()));
+        }
+    }
+
+    private function balanceForRequest(AbsenceRequest $request): AbsenceBalance
+    {
+        /** @var User $user */
+        $user   = $request->getUser();
+        $type   = $request->getType();
+        $period = $this->periodFor($user, $type, $request->getStartDate());
+
+        return $this->getOrCreateBalance($user, $type, $period);
+    }
+
+    private function shouldTrack(AbsenceRequest $request): bool
+    {
+        $type = $request->getType();
+
+        return null !== $type && $type->decrementsBalance() && null !== $request->getUser();
+    }
+}