PrivCommand class

Describes a non-interactive process to start in the connected server.

The command executes arguments directly. No shell is added implicitly, so pass ['/system/bin/sh', '-c', script] when shell parsing is needed.

This class is written by hand rather than generated, because it validates its input at construction time and exposes unmodifiable collections. Both behaviours are part of its contract: the checks reject values that the native runtime would otherwise reject later with a less useful error.