Fcitx service does not start without the program
Pull request 11694, merged into quattro, keeps the fcitx5 user service from starting when the program is absent. therk wrote that one aarch64 image had restarted it 20943 times, with 105828 journal lines.
The service is set to restart 2 seconds after a failure, and the first-run script enables it even when the image does not ship fcitx5. The unit requires the program to be present, the same guard the Tailscale receive service uses, and it stays enabled without running.