Follow-up: cheap live MAX_STEPS=3 smoke on post-merge Track A SHA #84

Context

Optional follow-up from Track A smoke on #83. Not a merge blocker — live MAX_STEPS=3 mid-run stop was already proved on 5830499 (Step budget exceeded (3/3)); suite 466/466 green on head.

Ask

Cheap live Haiku (or equivalent) harness smoke on the post-merge main SHA with OASIS_HARNESS=true, OASIS_HARNESS_MAX_STEPS=3, OASIS_HARNESS_HARD_STOP=true, confirm mid-run stop still fires and artifacts validate.

Done when

• Live run stops with step budget exceeded at 3/3
• Findings + coverage validators pass on produced artifacts
• Note the SHA smoked in this issue

Close if we decide the pre-merge Research proof is enough and we do not want another paid run.