This commit adds key reveal to MuSig2 loopin swaps' success path. In
this case the client reveals their internal HTLC key to the server when
the swap invoice is settled. With this key the server can sweep the swap
HTLC without any more interaction from the client. We'll do this every
block (after the invoice has been settled).
This commit changes how we create loopin swaps if the client activates
the experimental MuSig2 features. When creating a new loopin swap the
client will create (and store) a new key that will be used as the
sender's internal key when constructing the HTLC. The client will send
the public part to the server and will also receive (and store) the
server's (receiver) internal public key.
This commit bumps LND and lndclient to make it possible to upgrade
taproot HTLC construction with a MuSig2 version. This is required to
support both old (MuSig2 0.4) and new (MuSig2 1.0) clients.
In this commit we deprecate the sighash field from the
MuSig2SignSweepReq request in favour of using a psbt serialized sweep
transaction instead. This way the sever gains full transparency about
client sweep requests and can assemble the sighash to sign on its own.
In this commit we add a call to the new probe endpoint directly into the
loop-in quote call. Furthermore we add an option to include private
channels in the loopin swap payment request. This is also useful for when
users quote/probe directly using the client API and specify hop hints.
Once we have revealed our preimage to the world with a sweep attempt,
we can safely push our preimage to the server to speed up on chain
claim.
Rather than rely on the server, we use the state of our invoice in lnd
to determine whether we should continue trying to push the preimage to
the server.
We update to new set of server protos where new Terms calls are added.
Here static information will be returned from the server.
We no longer have a feebase+feerate, but get a final fee directly
returned by the server.
