feat(absences) : avancement module absences + suppression du portail client

Deux lots regroupés sur la branche feat/absence-management.

Suppression complète du portail client :
- retire ROLE_CLIENT (security.yaml) ; User::getRoles() ajoute toujours ROLE_USER
- supprime l'entité ClientTicket (+ repo, states, relations), User.client et
  User.allowedProjects, NotificationService, ProjectAllowedExtension, le bloc
  ROLE_CLIENT de MailAccessChecker
- front : pages /portal, layout portal, composants client-ticket/,
  AdminClientTicketTab, services/dto/i18n/docs associés
- fixtures : retire les users client-liot / client-acme
- migration Version20260522110000 (drop client_ticket, user_allowed_projects,
  colonnes liées ; task_document.task_id -> NOT NULL)
- tests : retire les cas obsolètes testant le blocage des clients sur le mail

Module gestion des absences (WIP) :
- entités / migrations (Version20260521160000, Version20260522090000)
- pages absences.vue / team-absences.vue, composants frontend/components/absence/
- services front, AccrueLeaveCommand, PublicHolidayController

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

src/Repository/UserRepository.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Repository;
 
 use App\Entity\User;
+use DateTimeInterface;
 use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
 use Doctrine\Persistence\ManagerRegistry;
 
@@ -38,4 +39,24 @@ class UserRepository extends ServiceEntityRepository
             ->getResult()
         ;
     }
+
+    /**
+     * Employees active on the given date (hired on/before it, not yet left).
+     *
+     * @return User[]
+     */
+    public function findActiveEmployees(DateTimeInterface $date): array
+    {
+        $dateStr = $date->format('Y-m-d');
+
+        return $this->createQueryBuilder('u')
+            ->where('u.isEmployee = true')
+            ->andWhere('u.hireDate IS NULL OR u.hireDate <= :date')
+            ->andWhere('u.endDate IS NULL OR u.endDate >= :date')
+            ->setParameter('date', $dateStr)
+            ->orderBy('u.username', 'ASC')
+            ->getQuery()
+            ->getResult()
+        ;
+    }
 }