[bug]: CommitSig deficiency causes HTLCs insufficiently populated on node restart

[dstadulis]

Background

[incomplete background]

1. In the scenario where one nodes hangs during of path finding,
2. The data which lnd CommitSig handles ?results in a deficient state
3. Which results in downstream uses of lnd (tapd in this case) where HT sigs are blank

Initial CommitSig deficiency

https://github.com/lightningnetwork/lnd/blob/dcd921ad6945f26dd9786b025f45aab944d13d68/lnwallet/channel.go#L4096-L4108

This should be set:

https://github.com/lightningnetwork/lnd/blob/1b353b0bfd58a6dfeafc2878111404048826b41d/lnwallet/channel.go#L4745

TODO

• [ ] Assess if these gaps could causes UnpackSigs to fail: https://github.com/lightninglabs/taproot-assets/blob/8eb6c5345f77d07b07ca9fbb5a76943678049eff/tapchannel/aux_leaf_signer.go#L147