Fix modal label display issues and DOM node removal errors

- Hide rounded background labels in modal (계약구분, 국내/해외, 기본 버튼)
- Add try-catch blocks for DOM operations to prevent removeChild errors
- Fix event listener registration/removal in RealtimePreview, FileUpload, FileComponentConfigPanel
- Improve error handling for CustomEvent dispatching

frontend/components/screen/InteractiveScreenViewer.tsx

@@ -1726,19 +1726,19 @@ export const InteractiveScreenViewer: React.FC<InteractiveScreenViewerProps> = (
 
   return (
     <>
-      <div className="h-full w-full rounded-xl border border-gray-200/60 bg-gradient-to-br from-white to-gray-50/30 p-4 shadow-sm transition-all duration-200 hover:shadow-md">
-        {/* 라벨이 있는 경우 표시 (데이터 테이블 제외) */}
-        {shouldShowLabel && (
-          <div className="block mb-3" style={labelStyle}>
-            <div className="inline-flex items-center bg-gray-100 px-3 py-1 rounded-lg text-sm font-semibold">
-              {labelText}
-              {component.required && <span style={{ color: "#f97316", marginLeft: "4px" }}>*</span>}
+      <div className="h-full w-full">
+          {/* 라벨이 있는 경우 표시 (데이터 테이블 제외) */}
+          {shouldShowLabel && (
+            <div className="block mb-3" style={labelStyle}>
+              <div className="inline-flex items-center bg-gray-100 px-3 py-1 rounded-lg text-sm font-semibold">
+                {labelText}
+                {component.required && <span style={{ color: "#f97316", marginLeft: "4px" }}>*</span>}
+              </div>
             </div>
-          </div>
-        )}
+          )}
 
         {/* 실제 위젯 */}
-        <div className="flex-1 rounded-lg overflow-hidden">{renderInteractiveWidget(component)}</div>
+        <div className="h-full w-full">{renderInteractiveWidget(component)}</div>
       </div>
 
       {/* 개선된 검증 패널 (선택적 표시) */}