Add YYLO Benchmark to 5a · Eval frameworks & harnesses

[InsightFactoryAPP]

Affiliation disclosure, up front: I maintain YYLO — this is a self-submission, disclosed per the CONTRIBUTING bar ("If you wrote or maintain the resource, say so in the PR body. Self-submissions are welcome… undisclosed ones are not").

What: one-line entry at the bottom of §5a, following the shape of the two most recent additions to that section (Caliper #34, Coder Eval #61). One change per PR; README only.

Why §5a: YYLO Benchmark is a code-first test-runner. It normalizes every case into one v2 attempt contract, runs each candidate in a private fresh-repository workspace (default candidate subprocesses sit behind a selective filesystem sandbox), and grades retained evidence with ordered deterministic and/or LLM-judge profiles. The angle none of the current §5a entries own is evidence integrity: workspace receipts, post-execution repository manifests, and evaluator provenance are hash-linked, and report/doctor/re-evaluation verify that complete chain before anything is published — "immutable evidence for agent runs" is the repo's own one-line description. Runs as yylo-benchmark, or yy benchmark delegated from the YYLO orchestrator CLI (https://github.com/yylo-dev/yylo).

Adoption evidence, honestly stated: the benchmark repo is 18 days old (created 2026-08-17) and currently shows 1★ — the star number alone fails the "evidence someone else uses them" test, and I'd rather say that than have you find it. The external-use evidence I can actually offer:

• npm @yylo/benchmark: 151 downloads in the last month (api.npmjs.org/downloads/point/last-month/@YyLo%2Fbenchmark, checked at submission)
• The parent orchestrator CLI that delegates yy benchmark (yylo-dev/yylo): ~54 external stars over ~8 months of daily development; @yylo/cli 563 downloads last month (same API)
• Both repos MIT-licensed, pushed daily, with test suites

If that still reads as "come back later," that's a fair call and I'll re-submit when the benchmark repo's own numbers are stronger. Per "every number must be quotable," the annotation itself carries no figures; every claim above traces to the linked README, the repo About line, or the npm downloads API.