ReadonlyfixedThe fixed simulation step, in seconds (§10). Must be finite and > 0.
Optional ReadonlymetadataFree-form JSON the caller wants pinned to the recording: a scenario name, a build id, a date the caller read. Validated and deep-copied.
Optional ReadonlyseedThe run's RNG seed (§33), when there is one.
Optional ReadonlysnapshotCapture a periodic snapshot roughly every N simulation steps (§34).
Omit — or pass 0 — for none. See ReplayRecorder.recordFrame for
exactly where the snapshots land.
How a recording session is configured (§34).