[jiaooo-2]

Problem

freeze_round records SHA256 and byte size for every round input and output, but gate --round-dir previously checked only the split file. A changed snapshot or eval input could go unnoticed while a round passed the gate.

Change

• Add self_evolve verify --round-dir ... to check the manifest and every recorded file. It writes verification_result.json and returns a nonzero status on failure.
• Make gate --round-dir reject a round when any frozen file differs.
• Document relative-path handling and add regression tests.

Validation

• 39 targeted tests passed locally, including a case where scores pass but a changed snapshot makes the gate reject the round.
• The fatal flake8 checks and git diff --check passed.
• The full pytest suite could not run locally because project dependencies are missing; GitHub Actions will run the repository test matrix.

Refs #97.