fix: [문서양식] 미리보기 이미지 MNG API 프록시 경유로 수정 (브라우저→MNG→API→R2)

app/Http/Controllers/Api/Admin/DocumentTemplateApiController.php

@@ -927,4 +927,39 @@ private function checkLinkedItemDuplicates(?string $category, array $newItemIds,
             'errors' => ['linked_items' => $messages],
         ], 422);
     }
+
+    /**
+     * R2 image_path → presigned URL 프록시 (미리보기용)
+     */
+    public function presignedUrlByPath(Request $request): JsonResponse
+    {
+        $path = $request->input('path');
+        if (empty($path)) {
+            return response()->json(['url' => null], 400);
+        }
+
+        $baseUrl = config('services.api.base_url', 'https://api.sam.kr');
+        $internalUrl = config('services.api.internal_url');
+        $apiKey = config('services.api.key');
+
+        $headers = [
+            'X-API-KEY' => $apiKey,
+            'X-TENANT-ID' => session('selected_tenant_id', 1),
+        ];
+
+        if ($internalUrl) {
+            $headers['Host'] = parse_url($baseUrl, PHP_URL_HOST) ?: 'api.sam.kr';
+            $baseUrl = $internalUrl;
+        }
+
+        $response = Http::baseUrl($baseUrl)
+            ->withoutVerifying()
+            ->withHeaders($headers)
+            ->timeout(10)
+            ->post('/api/v1/files/presigned-url-by-path', ['path' => $path]);
+
+        return response()->json([
+            'url' => $response->successful() ? $response->json('data.url') : null,
+        ]);
+    }
 }