fix(skill): 修正上传 Skill 安装包结构

scripts/package-upload-skill.ps1

@@ -38,7 +38,20 @@ Add-Type -AssemblyName System.IO.Compression.FileSystem
   $sourcePath,
   $packagePath,
   [System.IO.Compression.CompressionLevel]::Optimal,
-  $true
+  $false
 )
 
+$archive = [System.IO.Compression.ZipFile]::OpenRead($packagePath)
+try {
+  $entries = @($archive.Entries | ForEach-Object { $_.FullName.Replace('\', '/') })
+  if ($entries -notcontains 'SKILL.md') {
+    throw 'Packaged Skill must contain SKILL.md at the ZIP root.'
+  }
+  if ($entries | Where-Object { $_ -like "$skillName/*" }) {
+    throw 'Packaged Skill contains an extra top-level directory.'
+  }
+} finally {
+  $archive.Dispose()
+}
+
 Write-Output $packagePath