Constant CWD_STATE_FILE_OVERRIDE_ENV 

const CWD_STATE_FILE_OVERRIDE_ENV: &str = "AGENTMUX_BASHWRAP_CWD_STATE_FILE";

Optional override of the state file’s own path, read from bashwrap’s own process env (distinct from CWD_STATE_ENV, which bashwrap sets rather than reads). Exists so tests can point persistence at a tempdir instead of a real agent’s ~/.agentmux state, and as an escape hatch for manual debugging.