Step 0 — Implementation Detail

Recorded functional requirements for authenticated API, transactional persistence, asynchronous events, retries/dead lettering, observability, and repeatable Terraform.
Recorded availability, latency, security, scalability, auditability, and no-provisioning validation targets.
Separated constraints, assumptions, and unresolved production questions into requirements.md.
Set product_selection_deferred to true in requirements.md and workflow.yaml.