Module error 

Dedicated error enums for each ExecutionService verb.

All error types are closed enums (no #[non_exhaustive]): wire consumers must handle every variant, and the adapter layer converts to a string before crossing the MCP boundary (design-v1.md §2).

All error types derive serde::Serialize + serde::Deserialize so they can be embedded in structured JSON responses if needed by callers.

Enums

AwaitError

Error returned by crate::execution::ExecutionService::await_terminal.

CancelError

Error returned by crate::execution::ExecutionService::cancel.

ObserveError

Error returned by crate::execution::ExecutionService::observe.

ObserverRecvError

Error returned by crate::execution::ObserverHandle::recv and crate::execution::ObserverHandle::try_recv.

ResumeError

Error returned by crate::execution::ExecutionService::resume.

SpawnError

Error returned by crate::execution::ExecutionService::spawn.

StateError

Error returned by crate::execution::ExecutionService::state.