test ant/term ↗

fix: headless entrypoint needs sway/grim, and must reap sway by real pid Two blockers once XDG_RUNTIME_DIR (ci-tron's own fix) let the headless smoke test actually start: - flake.nix's devShell already bundled wlrctl/wl-clipboard for this exact test but never sway or grim themselves — scripts/headless_test.py needs both, and had no way to get them on a host that doesn't happen to have a desktop environment already providing them system-wide (a bare CI box, for instance). - On a host with no logind session for this seat — nothing registers one for ci-tron-runner's sudo session, same root cause as the XDG_RUNTIME_DIR fix — sway double-forks and detaches, reparenting to init. start_sway's own Popen then tracks a pid that's already exited, not the real compositor: find_sway_ipc_socket was matching the IPC socket by that stale pid (so it could never find sway's real one) and the process a broken run's `finally` tried to terminate() wasn't the real compositor either, leaking sway/swaybar/swaybg past every run — confirmed by hand (orphaned sway processes still running from a reproduction). Recovers the real pid from the IPC socket's own name instead ("sway-ipc.<uid>.<pid>.sock" — authoritative, unlike the Popen handle), and reaps it with a plain kill(2)/proc-poll loop since it's not our child (waitpid(2) can't see it). Verified end-to-end as ci-tron-runner itself on the ci-tron host, including confirming no leaked processes across repeated runs. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KpDBFeBQKx9f5U3pfVeVV3