feat: add multi-city representation support and domain context resolution

- Created migration to add representation_cities table and domain, is_global fields to representations.
- Implemented SiteContextController to resolve domain to site context (city | representation | unknown).
- Developed DomainContext and DomainContextResolver services for domain mapping.
- Added tests for DomainContextResolver and commission logic based on domain ownership.

src/Location/Repository/CityRepository.php

@@ -28,6 +28,11 @@ class CityRepository extends ServiceEntityRepository
         return $qb->getQuery()->getResult();
     }
 
+    public function findByDomain(string $domain): ?City
+    {
+        return $this->findOneBy(['domain' => $domain]);
+    }
+
     public function save(City $city, bool $flush = true): void
     {
         $this->getEntityManager()->persist($city);