- Move unit file from services/systemd/helsinki-a/ to
services/thiswebsitedoesnotexist/ (matches systemd_services role convention)
- Add systemd_services: [thiswebsitedoesnotexist] to helsinki-a host_vars
- Add systemd_services role to helsinki-a stage in deploy.yml
- Remove redundant caddy.service (apt manages this via the caddy role)
Closes PESO-117
