Δ6 — User-overridable wall-clock cap (Step Function executionTimeout param)

[jack-champagne]

C0. Today's hardcoded SSM executionTimeout=21600 (6 h) becomes a submit-time parameter (default 21600). On cap → TerminateInstances + write FINISHED{aborted} to S3. (You flagged fixed caps as 'silly' — this makes it overridable per solve.)

Acceptance (TDD): a submit with max_wallclock=600 is killed at ~600 s with FINISHED{aborted} written + instance terminated; omitting it defaults to 6 h.

⛔ Gate: blocked by the wk-3 freeze — run-dir contract + SchemaPackage v0 (amicode #15 + the #28–31 stack). RemoteExecutor/the S3 layout is the run-dir contract, so do not start until that lands.

📄 Refs: Spec armonissima/specs/spec-20260628-amicode-cloud-solve-service.md (Δ6) · phased plan §5a (plan-20260603-124231-amicode-phased-build) · aws-infra/INFRASTRUCTURE.md → The Analysis Pipeline (reuse step_function/ec2_launch_template/dynamodb/runner_image).

Evolve, not build — a working v0 (the aws-infra Analysis Pipeline) already does size→S/M/L EC2→julia→S3→email→terminate. Validate on staging (mirrors prod), then two-step promote.

🏗 Implementation repo: aws-infra (Terraform / lambda / Image Builder). Infra-side reference: harmoniqs/aws-infra#129.