Saving .scss files does a full browser page refresh instead of live reloading just the css update

Everything works correctly except when saving .scss files the browser does a full page refresh instead of live reloading just the css change.

Using:
```
"@11ty/eleventy": "^2.0.0",
"@11tyrocks/eleventy-plugin-sass-lightningcss": "^1.0.1",
```

When I use just plain `"sass": "^1.58.3"` with a `--watch` flag as a task alongside `npx @11ty/eleventy --serve` the updated styles live reload as expected.

Wonder if there's some config I'm missing.

Look at the plugin's source code to understand how it triggers rebuilds and live reloads. Compare the behavior with plain sass --watch. Check the Eleventy serve mode and how file changes are detected. The goal is to make .scss file saves trigger a CSS-only live reload instead of a full page refresh.

索引モデルが issue の本文から書いたものです。