Missing preconnect to plausible domain for performance

When proxy is not used, I think the module should automatically add a `<link rel="preconnect" :href="plausibleDomain">` to the `head`
<img width="648" height="284" alt="Image" src="https://github.com/user-attachments/assets/56971685-1b3a-4855-8ce1-06ef896faa59" />