Module completion 

CompletionHandle, CompletionSink, ContractResponse. CompletionHandle for async Contract methods. Implementations call [CompletionHandle::complete]; the handle routes through a [CompletionSink] (typically IngressQueue), which the engine drains on its next poll to unpark the suspended op.

Structs

CompletionHandle

Async handle the Contract method holds. Carries the CommandId

Enums

ContractResponse

Contract-layer mirror of crate::atomic::DispatchResult. Now(Ok) → Immediate (boxed straight into the slot table); Now(Err) → dispatch error; Later → Async(cmd_id).

Traits

CompletionSink

Cross-thread completion delivery. Sinks take borrowed slices and must copy into framework-owned storage before returning (Principle 1a: external byte payloads are ephemeral).