Built-in provider profile for the Cursor Agent CLI (agent).
Cursor uses headless -p execution with stream-json output. The prompt is a
positional argument at the end of argv; there is no --prompt flag. When
:cwd is supplied it is used both as the process working directory and as the
Cursor --workspace argument.
Governed launches follow the shared GovernedAuthority contract: command,
cwd, env, and clear-env state come only from the materialized authority.
config_root and auth_root are metadata; materializers must place any
required Cursor paths into authority.env.