refactor:법인도장 저장소를 GCS로 변경 (로컬/서버 환경 무관)

- 업로드: base64 → 임시파일 → GCS 업로드
- 조회: GCS signed URL 반환 (60분 유효)
- 삭제: GCS 객체 삭제 + tenant_settings 삭제
- 계약 생성 시: GCS에서 다운로드 → 로컬 저장 → signer에 설정
- tenant_settings 값: image_path → gcs_object로 변경

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

app/Http/Controllers/ESign/EsignApiController.php

@@ -12,6 +12,7 @@
 use App\Models\ESign\EsignSignField;
 use App\Models\ESign\EsignAuditLog;
 use App\Models\Tenants\TenantSetting;
+use App\Services\GoogleCloudStorageService;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\DB;
@@ -32,24 +33,21 @@ public function getStamp(): JsonResponse
             ->where('setting_key', 'company_stamp')
             ->first();
 
-        if (!$setting || empty($setting->setting_value['image_path'])) {
+        if (!$setting || empty($setting->setting_value['gcs_object'])) {
             return response()->json(['success' => true, 'data' => null]);
         }
 
-        $path = $setting->setting_value['image_path'];
-        if (!Storage::disk('local')->exists($path)) {
+        $gcs = app(GoogleCloudStorageService::class);
+        $signedUrl = $gcs->getSignedUrl($setting->setting_value['gcs_object'], 60);
+
+        if (!$signedUrl) {
             return response()->json(['success' => true, 'data' => null]);
         }
 
-        $content = Storage::disk('local')->get($path);
-        $mime = Storage::disk('local')->mimeType($path) ?: 'image/png';
-        $dataUrl = 'data:' . $mime . ';base64,' . base64_encode($content);
-
         return response()->json([
             'success' => true,
             'data' => [
-                'image_path' => $path,
-                'image_url' => $dataUrl,
+                'image_url' => $signedUrl,
             ],
         ]);
     }
@@ -70,14 +68,31 @@ public function uploadStamp(Request $request): JsonResponse
             return response()->json(['success' => false, 'message' => '이미지 데이터가 올바르지 않습니다.'], 422);
         }
 
-        $path = "esign/{$tenantId}/stamps/company_stamp.png";
-
-        // 기존 파일이 있으면 삭제
-        if (Storage::disk('local')->exists($path)) {
-            Storage::disk('local')->delete($path);
+        $gcs = app(GoogleCloudStorageService::class);
+        if (!$gcs->isAvailable()) {
+            return response()->json(['success' => false, 'message' => 'GCS 설정이 되어 있지 않습니다.'], 500);
         }
 
-        Storage::disk('local')->put($path, $imageData);
+        // 기존 GCS 파일 삭제
+        $existing = TenantSetting::where('tenant_id', $tenantId)
+            ->where('setting_group', 'esign')
+            ->where('setting_key', 'company_stamp')
+            ->first();
+        if ($existing && !empty($existing->setting_value['gcs_object'])) {
+            $gcs->delete($existing->setting_value['gcs_object']);
+        }
+
+        // 임시 파일에 저장 후 GCS 업로드
+        $tmpFile = tempnam(sys_get_temp_dir(), 'stamp_');
+        file_put_contents($tmpFile, $imageData);
+
+        $gcsObject = "esign/{$tenantId}/stamps/company_stamp.png";
+        $gcsUri = $gcs->upload($tmpFile, $gcsObject);
+        unlink($tmpFile);
+
+        if (!$gcsUri) {
+            return response()->json(['success' => false, 'message' => 'GCS 업로드에 실패했습니다.'], 500);
+        }
 
         TenantSetting::updateOrCreate(
             [
@@ -86,20 +101,18 @@ public function uploadStamp(Request $request): JsonResponse
                 'setting_key' => 'company_stamp',
             ],
             [
-                'setting_value' => ['image_path' => $path],
+                'setting_value' => ['gcs_object' => $gcsObject],
                 'updated_by' => auth()->id(),
             ]
         );
 
-        $mime = Storage::disk('local')->mimeType($path) ?: 'image/png';
-        $dataUrl = 'data:' . $mime . ';base64,' . base64_encode($imageData);
+        $signedUrl = $gcs->getSignedUrl($gcsObject, 60);
 
         return response()->json([
             'success' => true,
             'message' => '법인도장이 등록되었습니다.',
             'data' => [
-                'image_path' => $path,
-                'image_url' => $dataUrl,
+                'image_url' => $signedUrl,
             ],
         ]);
     }
@@ -116,9 +129,10 @@ public function deleteStamp(): JsonResponse
             ->first();
 
         if ($setting) {
-            $path = $setting->setting_value['image_path'] ?? null;
-            if ($path && Storage::disk('local')->exists($path)) {
-                Storage::disk('local')->delete($path);
+            $gcsObject = $setting->setting_value['gcs_object'] ?? null;
+            if ($gcsObject) {
+                $gcs = app(GoogleCloudStorageService::class);
+                $gcs->delete($gcsObject);
             }
             $setting->delete();
         }
@@ -287,22 +301,30 @@ public function store(Request $request): JsonResponse
             ]);
         }
 
-        // 법인도장 자동 적용: tenant_settings에 등록된 도장이 있으면 creator signer에 설정
+        // 법인도장 자동 적용: GCS에서 다운로드 → 로컬 저장 → signer에 설정
         $stampSetting = TenantSetting::where('tenant_id', $tenantId)
             ->where('setting_group', 'esign')
             ->where('setting_key', 'company_stamp')
             ->first();
 
-        if ($stampSetting && !empty($stampSetting->setting_value['image_path'])) {
+        if ($stampSetting && !empty($stampSetting->setting_value['gcs_object'])) {
             $creatorSigner = EsignSigner::withoutGlobalScopes()
                 ->where('contract_id', $contract->id)
                 ->where('role', 'creator')
                 ->first();
 
             if ($creatorSigner) {
-                $creatorSigner->update([
-                    'signature_image_path' => $stampSetting->setting_value['image_path'],
-                ]);
+                $gcs = app(GoogleCloudStorageService::class);
+                $signedUrl = $gcs->getSignedUrl($stampSetting->setting_value['gcs_object'], 5);
+
+                if ($signedUrl) {
+                    $imageData = @file_get_contents($signedUrl);
+                    if ($imageData) {
+                        $localPath = "esign/{$tenantId}/signatures/{$contract->id}_{$creatorSigner->id}_stamp.png";
+                        Storage::disk('local')->put($localPath, $imageData);
+                        $creatorSigner->update(['signature_image_path' => $localPath]);
+                    }
+                }
             }
         }