_v1: expose a step-script deserializer (no way to decode a bare StepScript)

[seant-aws]

Gap

The _openjd_rs binding exposes deserialize_step, which requires a full named step object. There is no entry point to deserialize a bare step script.

Consequence

Callers that hold a StepScript (e.g. the deadline-cloud-worker-agent's RustSessionRuntime adapter in aws-deadline/deadline-cloud-worker-agent#1002) must fabricate a synthetic wrapper — {"name": "Placeholder", "script": ...} — and pull .script off the deserialized step. Functional, but the synthetic name can leak into Rust-side validation error messages and confuse whoever reads the session log.

Proposal

Expose a deserialize_step_script-style function (binding and/or crate) that decodes a bare script object directly.

Related: #332 (run-task-without-session-env capability for the same adapter).

[seant-aws]

Closing. Since filing this, we've confirmed the synthetic wrapper is lower-impact than it first appeared: WrappedStep.Name (RFC 0008 wrap actions) is resolved from the step_name argument to run_task, not from the deserialized step's name — so the placeholder name never affects execution semantics. The remaining impact is cosmetic: the synthetic name can appear in Rust-side validation error messages for a malformed script. That alone doesn't justify a new deserializer API surface, and the ~18-line wrapper in the worker agent adapter is stable and covered by tests. Happy to reopen if another consumer needs to decode a bare StepScript.

[seant-aws]

Closing. Since filing this, we've confirmed the synthetic wrapper is lower-impact than it first appeared: WrappedStep.Name (RFC 0008 wrap actions) is resolved from the step_name argument to run_task, not from the deserialized step's name — so the placeholder name never affects execution semantics. The remaining impact is cosmetic: the synthetic name can appear in Rust-side validation error messages for a malformed script. That alone doesn't justify a new deserializer API surface, and the small wrapper in the worker agent adapter is stable and covered by tests. Happy to reopen if another consumer needs to decode a bare StepScript.