[cryptography] Introduce `RBSR`#2665

Draft

patrick-ogrady wants to merge 21 commits intomainfrom

claude/rbsr-set-reconciliation-jbyZk

Commits on Jan 1, 2026

[cryptography] Add Range-Based Set Reconciliation (RBSR/Negentropy) module
claude
committed
[cryptography/rbsr] Use sha256::Digest type for item IDs
claude
committed
[cryptography/rbsr] Use Blake3 instead of SHA-256 for fingerprint finalization
claude
committed
[cryptography/rbsr] Use LtHash for fingerprint accumulation
claude
committed
[cryptography/rbsr] Simplify by using LtHash and Blake3 directly
claude
committed
[cryptography/rbsr] Fix IdList exchange and add comprehensive tests
claude
committed

Commits on Jan 2, 2026