docs: add tip for using HTML reporter on CI

docs/guide/ui.md

@@ -53,6 +53,19 @@ npx vite preview --outDir ./html
 You can configure output with [`outputFile`](/config/outputfile) config option. You need to specify `.html` path there. For example, `./html/index.html` is the default value.
 :::
 
+::: tip
+To view the HTML report from CI, for example in GitHub Actions, upload the output directory as an artifact:
+
+```yaml
+- uses: actions/upload-artifact@v4
+  with:
+    name: vitest-report
+    path: html/
+```
+
+Download and extract it, then run `vite preview` locally as above — or open the zip directly in [Zipview](https://zipview.hiro18181.workers.dev/) without any local setup.
+:::
+
 ## Module Graph
 
 Module Graph's tab displays the module graph of the selected test file.