TASK-062: persist 45 unworked review findings

Captures the test-quality / code-quality / spec-alignment review pass
on the digest factory + handshake work. Note: major finding #1 (HA1
resources still on the legacy static-challenge overload) is resolved
by the previous commit; the remaining 44 findings stay open for
follow-up tasks per the milestone audit.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: etr