The TSS signing was failing with "U doesn't equal T" error because
tss-party was passing incorrect parameters to tss.NewParameters():
- Was: len(sortedPartyIDs)=3 (signing participants), thresholdT-1=2
- Now: thresholdN=5 (keygen N), thresholdT=3 (keygen T)
This matches how pkg/tss/signing.go creates parameters in server-party,
which uses TotalParties=N and Threshold=T from the original keygen.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>