fix(admin-web): disable backdrop click to close upload modal

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

frontend/admin-web/src/views/app-versions/AppVersionManagementPage.tsx

@@ -266,8 +266,8 @@ const UploadModal: React.FC<{
   const handleClose = () => { reset(); onClose(); };
 
   return (
-    <div style={overlayStyle} onClick={handleClose}>
-      <div style={modalStyle} onClick={(e) => e.stopPropagation()}>
+    <div style={overlayStyle}>
+      <div style={modalStyle}>
         <h2 style={{ margin: '0 0 8px' }}>{t('app_version_upload')}</h2>
 
         <label style={labelStyle}>{t('app_version_upload_file')}</label>