Vanadium implements per-site content filtering as a usability feature via Chromium's in-built filtering engine [0]. They currently use EasyList & EasyPrivacy filters which are quite popular and also a prominent default in uBlock Origin [1].
[0] https://grapheneos.org/features#vanadium
[1] https://github.com/gorhill/uBlock?tab=readme-ov-file#ublock-...