feat(mcp) : add CRUD tools for Sites, Constructeurs, Products

- 5 tools each: list, get, create, update, delete
- McpToolHelper extracted to AbstractApiTestCase for reuse
- DashboardStatsToolTest simplified to use base helpers
- 22 MCP tests pass

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

src/Mcp/Tool/Site/GetSiteTool.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Mcp\Tool\Site;
+
+use App\Mcp\Tool\McpToolHelper;
+use App\Repository\SiteRepository;
+use Mcp\Capability\Attribute\McpTool;
+
+#[McpTool(
+    name: 'get_site',
+    description: 'Get a single site by ID with all its details (name, contact info, address).',
+)]
+class GetSiteTool
+{
+    use McpToolHelper;
+
+    public function __construct(
+        private readonly SiteRepository $sites,
+    ) {}
+
+    public function __invoke(string $siteId): array
+    {
+        $site = $this->sites->find($siteId);
+
+        if (!$site) {
+            $this->mcpError('not_found', "Site not found: {$siteId}");
+        }
+
+        return $this->jsonResponse([
+            'id'                => $site->getId(),
+            'name'              => $site->getName(),
+            'contactName'       => $site->getContactName(),
+            'contactPhone'      => $site->getContactPhone(),
+            'contactAddress'    => $site->getContactAddress(),
+            'contactPostalCode' => $site->getContactPostalCode(),
+            'contactCity'       => $site->getContactCity(),
+            'color'             => $site->getColor(),
+            'createdAt'         => $site->getCreatedAt()->format('Y-m-d H:i:s'),
+            'updatedAt'         => $site->getUpdatedAt()->format('Y-m-d H:i:s'),
+        ]);
+    }
+}