Module error 

Full-flavor engine error envelope.

Mirrors the wrap-not-embed pattern: full errors wrap lean errors via From<memstead_base::EngineError>, so full code paths can transparently propagate a lean failure without re-wrapping at each call site. The full MCP render layer reads the wrapped chain to produce the typed code; the lean render layer only ever sees lean errors.

The four lifecycle-only variants live here rather than on memstead_base::EngineError: they are produced by this crate’s mem-management orchestrator (create_mem / delete_mem), which returns Result<_, FullEngineError>, so the lean crate carries no full-specific lifecycle types.

Enums

FullEngineError

Errors surfaced by the full engine extension.

RecoveryAction

Recovery shape for create_mem against pre-existing storage residue. A single enum field with three variants structurally enforces mutual exclusion on the wire (a three-boolean shape would need a runtime-validation step instead).