fix:법인도장 이미지를 base64 data URL로 반환 (local disk 404 해결)

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

app/Http/Controllers/ESign/EsignApiController.php

@@ -37,14 +37,20 @@ public function getStamp(): JsonResponse
         }
 
         $path = $setting->setting_value['image_path'];
-        $exists = Storage::disk('local')->exists($path);
+        if (!Storage::disk('local')->exists($path)) {
+            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' => $exists ? [
+            'data' => [
                 'image_path' => $path,
-                'image_url' => '/storage/' . $path,
-            ] : null,
+                'image_url' => $dataUrl,
+            ],
         ]);
     }
 
@@ -85,12 +91,15 @@ public function uploadStamp(Request $request): JsonResponse
             ]
         );
 
+        $mime = Storage::disk('local')->mimeType($path) ?: 'image/png';
+        $dataUrl = 'data:' . $mime . ';base64,' . base64_encode($imageData);
+
         return response()->json([
             'success' => true,
             'message' => '법인도장이 등록되었습니다.',
             'data' => [
                 'image_path' => $path,
-                'image_url' => '/storage/' . $path,
+                'image_url' => $dataUrl,
             ],
         ]);
     }