We can add more authorized paths to authorizedPaths if we need more resources to be pulled from the NewLeaf/Invidious backend on the same domain. This route forwards to the client a few headers like Bibliogram https://git.sr.ht/~cadence/bibliogram/tree/ea7cd5d5/item/src/site/api/proxy.js#L28-29 so we can also use this route to possibly proxy videos in the future. We are strict about the url parameter not overriding the NewLeaf/Invidious backend (instanceOrigin) by ensuring fetchURL has instanceOrigin as prefix.