Not sure on the specifics of how we're going to back search yet, but we'll need the following:
- /xrpc/app.bsky.actor.searchActors
- /xrpc/app.bsky.actor.searchActorsTypeahead
- /xrpc/app.bsky.feed.searchPosts
- /xrpc/app.bsky.unspecced.getPopularFeedGenerators (??)