Records the toolchain, replay result and SHA-256 of every file in the
branch's hardened 2.8 state, and points at the artifact actually
submitted (ramanujan-challenge-completed-submissions@1cbb598,
packages/problem_2_8) so this branch cannot be mistaken for it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GkHGb6KVF4adMScHNZEBM4
