Summary:
This is a follow-up to #35269
- Rename
different_keytodifferent_fieldinassert_musig_signer_data(discussion) - Use 3-argument
assert_equalfor pubnonce/partial-sig length checks, matching the pattern already used forfinalized["complete"](discussion) - Fix
MuSig2SessionIDdoc to say "signing pubkey" instead of "aggregate xonly key" (discussion)