Integration contract

Writes a spec's cross-repo seam to disk as a contract file and checks it with a smoke gate. A nominally single-project spec requires the consumer sweep below before reporting single project — no contract needed and stopping.

Inputs

<SPEC-ID> — the spec (PRD) / parent-issue identifier; take from context or ask once. User away and none inferable → stop with a Needs-user note — never guess which spec.

Rules