fix: release workflow 兼容已存在的 release + 版本号升到 4.2.0

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -24,9 +24,13 @@ jobs:
       - name: Tauri Build
         run: npx tauri build
 
-      - name: 创建 Release 并上传安装包
+      - name: 上传安装包到 Release
         run: |
           $installer = Get-ChildItem -Path "src-tauri\target\release\bundle\nsis\*.exe" | Select-Object -First 1
-          gh release create $env:GITHUB_REF_NAME "$installer" --title "$env:GITHUB_REF_NAME" --generate-notes
+          if (gh release view $env:GITHUB_REF_NAME 2>$null) {
+            gh release upload $env:GITHUB_REF_NAME "$installer" --clobber
+          } else {
+            gh release create $env:GITHUB_REF_NAME "$installer" --title "$env:GITHUB_REF_NAME" --generate-notes
+          }
         env:
           GH_TOKEN: ${{ github.token }}