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/Service/PdfCompressorService.php

@@ -6,6 +6,8 @@ namespace App\Service;
 
 class PdfCompressorService
 {
+    private ?bool $qpdfAvailable = null;
+
     /**
      * Compress an actual PDF file on disk. Returns metadata or null if no gain.
      *
@@ -13,8 +15,7 @@ class PdfCompressorService
      */
     public function compressFile(string $absolutePath): ?array
     {
-        exec('which qpdf', $qpdfPath, $returnCode);
-        if (0 !== $returnCode) {
+        if (!$this->isQpdfAvailable()) {
             return null;
         }
 
@@ -65,9 +66,7 @@ class PdfCompressorService
 
     public function compressBase64Pdf(string $base64Data): ?array
     {
-        // Check if qpdf is available
-        exec('which qpdf', $qpdfPath, $returnCode);
-        if (0 !== $returnCode) {
+        if (!$this->isQpdfAvailable()) {
             return null;
         }
 
@@ -127,4 +126,14 @@ class PdfCompressorService
             'saved'        => $originalSize - $compressedSize,
         ];
     }
+
+    private function isQpdfAvailable(): bool
+    {
+        if (null === $this->qpdfAvailable) {
+            exec('which qpdf', $qpdfPath, $returnCode);
+            $this->qpdfAvailable = 0 === $returnCode;
+        }
+
+        return $this->qpdfAvailable;
+    }
 }