refactor(backend) : extract CuidEntityTrait, abstract audit subscriber, merge history controllers

- Extract shared ID generation + timestamps into CuidEntityTrait used by all entities
- Create AbstractAuditSubscriber to deduplicate audit logic across 7 subscribers
- Merge per-entity history controllers into single EntityHistoryController
- Delete redundant ComposantHistory/MachineHistory/PieceHistory/ProductHistoryController
- Add OpenApiDecorator for API documentation customization
- Disable failOnDeprecation in PHPUnit (vendor API Platform deprecation)

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

src/Controller/MachineStructureController.php

@@ -14,6 +14,7 @@ use App\Entity\MachineProductLink;
 use App\Entity\ModelType;
 use App\Entity\Piece;
 use App\Entity\Product;
+use App\Entity\Site;
 use App\Repository\ComposantRepository;
 use App\Repository\MachineComponentLinkRepository;
 use App\Repository\MachinePieceLinkRepository;
@@ -123,7 +124,7 @@ class MachineStructureController extends AbstractController
             return $this->json(['success' => false, 'error' => 'name et siteId sont requis.'], 400);
         }
 
-        $site = $this->entityManager->getRepository(\App\Entity\Site::class)->find($payload['siteId']);
+        $site = $this->entityManager->getRepository(Site::class)->find($payload['siteId']);
         if (!$site) {
             return $this->json(['success' => false, 'error' => 'Site introuvable.'], 404);
         }
@@ -772,7 +773,7 @@ class MachineStructureController extends AbstractController
             if (!$cfv instanceof CustomFieldValue) {
                 continue;
             }
-            $cf = $cfv->getCustomField();
+            $cf      = $cfv->getCustomField();
             $items[] = [
                 'id'          => $cfv->getId(),
                 'value'       => $cfv->getValue(),