Command binary or shim name to resolve and execute.
CLI arguments array.
Execution constraints, standard input or protocol session, signal, and line callbacks.
Resolves with terminal stdout, stderr, exit code, and error envelopes.
Without a session, stdin receives stdinInput and is closed, and a stop forces
termination immediately. With a session, a stop first calls session.interrupt and
keeps delivering output so the session can observe the terminal event; the root is
stopped only when it has not exited within interruptGraceMs.
Executes a CLI executable or shim with robust streaming line decoders, buffer bounding, deadline enforcement, and layered termination.