Construction-time state for MJCLIRuntimeHost. Injectable so tests need no real TTY.
Optional
Whether this run may prompt — from ResolveInteractivity. Defaults to false (agent-first).
ResolveInteractivity
Defaults to process.stdout.isTTY.
process.stdout.isTTY
Construction-time state for MJCLIRuntimeHost. Injectable so tests need no real TTY.