feat(mcp) : add CRUD tools for Pieces, Composants, Machines

- 5 tools each: list, get, create, update, delete
- Piece: includes typePiece, constructeurs, prix (string)
- Composant: includes typeComposant, constructeurs, prix (string)
- Machine: includes site (required), constructeurs
- 40 MCP tests pass total

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Mcp/Tool/Piece/GetPieceTool.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Mcp\Tool\Piece;
+
+use App\Mcp\Tool\McpToolHelper;
+use App\Repository\PieceRepository;
+use Mcp\Capability\Attribute\McpTool;
+
+#[McpTool(
+    name: 'get_piece',
+    description: 'Get a single piece by ID with all its details, including typePiece and constructeurs.',
+)]
+class GetPieceTool
+{
+    use McpToolHelper;
+
+    public function __construct(
+        private readonly PieceRepository $pieces,
+    ) {}
+
+    public function __invoke(string $pieceId): array
+    {
+        $piece = $this->pieces->find($pieceId);
+
+        if (!$piece) {
+            $this->mcpError('not_found', "Piece not found: {$pieceId}");
+        }
+
+        $constructeurs = [];
+        foreach ($piece->getConstructeurs() as $c) {
+            $constructeurs[] = [
+                'id'   => $c->getId(),
+                'name' => $c->getName(),
+            ];
+        }
+
+        $typePiece = null;
+        if ($piece->getTypePiece()) {
+            $typePiece = [
+                'id'   => $piece->getTypePiece()->getId(),
+                'name' => $piece->getTypePiece()->getName(),
+            ];
+        }
+
+        return $this->jsonResponse([
+            'id'            => $piece->getId(),
+            'name'          => $piece->getName(),
+            'reference'     => $piece->getReference(),
+            'description'   => $piece->getDescription(),
+            'prix'          => $piece->getPrix(),
+            'typePiece'     => $typePiece,
+            'constructeurs' => $constructeurs,
+            'createdAt'     => $piece->getCreatedAt()->format('Y-m-d H:i:s'),
+            'updatedAt'     => $piece->getUpdatedAt()->format('Y-m-d H:i:s'),
+        ]);
+    }
+}