The selftest lived inside the paid skill-e2e-* file, so fixture-integrity
and plumbing pins executed weekly at best — a broken fixture would ship past
every gating check and be discovered when the periodic run burned money on a
dead instrument. Harness extracted to test/helpers/arm-benchmark-harness.ts,
selftest to test/arm-benchmark-selftest.test.ts (free suite). Touchfiles:
harness added to the three benchmark dep lists; the auq-repetition-cut-ab
tier comment now states the MANUAL re-run obligation honestly (periodic runs
force EVALS_ALL, so dep lists cannot auto-trigger it).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>