pub fn take_stable_exe_env()Expand description
Read AGENTMUX_STABLE_EXE and remove it from this process’s env, so no
child (host, srv, agent shells, a dev build started from a pane) inherits
a path that belongs to this launch. APPIMAGE is not used for the same
reason: the AppImage runtime’s copy leaks into every agent shell.
MUST be called from main before any thread exists (remove_var).