Summary

This PR isolates the discovery proof lane from the stacked launch-readiness work.

Included

• edit-preflight eval harness and frozen fixtures
• run-eval support for the edit-preflight lane
• comparator benchmark plumbing improvements
• focused eval and benchmark tests

Important

• checked-in result JSON was intentionally left untouched in this lane because it was not regenerated in this session
• this PR adds proof infrastructure, not new public outcome claims

Verification

• direct vitest run for tests/edit-preflight-harness.test.ts, tests/run-eval-config.test.ts, tests/benchmark-comparators.test.ts
• tsc -p tsconfig.json
• node scripts/run-eval.mjs --help
• node scripts/benchmark-comparators.mjs --dry-run