Currently Appreciate and Flag are anchor links to a URL.
Since these will be GET requests, by HTTP spec they should be idempotent, and browsers also hold this assumption. Chromium and other browser's Preload Pages/prefetching features are allowed to visit this URL in anticipation of the user clicking it, and may result in false positive flags/favorites.
For a simple no-JS solution, a good ol' HTML form with buttons would suffice to produce a POST request, rather than a GET request, which would prevent this issue from occurring.
<form action="/favorite" method="POST">
<input type="hidden" name="url" value="https://somesmallweb.site">
<button type="submit">Appreciate</button>
</form>
<form action="/flag" method="POST">
<input type="hidden" name="url" value="https://somesmallweb.site">
<button type="submit">Flag</button>
</form>
And can be styled by CSS to look the same as the current links.
