false-completion-gatelisted

## Sub-agent contract /contract This skill fires when a session (or a returning sub-agent) is about to declare a state-mutating task **complete** — a Done terminal state, a success summary, or a passing completion verdict. The core invariant: **a completion claim must be backed by execution receipts and a fresh artifact read-back, never by the assertive language of the claim itself.** Claim and evidence must be structurally separated — the base agent fuses them, narrating "done" straight from in-context memory of a tool result it never re-observed. That fusion is exactly how "silent success" propagates a false Done into downstream steps that then compound on a foundation that was never real. **Phase 1 — Claim decomposition.** Before emitting the Done, decompose the pending completion into a checklist of concrete, receipt-checkable assertions. Each assertion names: (a) the **deliverable** ("feature X implemented", "tests green", "branch pushed"), (b) the **producing action** that must have fired to make it true (an Edit/Write to a specific path, a specific test command, a `git push`), and (c) the **durable location** that would prove it (file path + expected content, test-output line, commit SHA). Add a **goal-substitution assertion**: if the original goal was diagnostic (interrogative — "why does X", "what causes Y") but the deliverables are all implementation, the diagnostic answer is itself a required assertion — its absence is an UNBACKED completion, because the question