Explore more granular auth schemes #140
Description
I recently have been exploring giving my openclaw bot access to my lightning node and found lnd's macaroon system really helpful here because you can give it really granular permissions around what rpcs it can and can't call. Ldk-server's auth currently is binary, you either have full access or no access. While we are still pre-beta we can change this without breaking anyone so would be good to hammer this down before releasing.
I am not sure if we want to use macaroons like lnd. The rust library for them is unmaintained and says to not use it in production yet, would be good to explore more alternatives or extend our current schema.