Currently it dumps server logs to stdout and only on failure. This can always be spat out if `COMPLEMENT_ALWAYS_PRINT_SERVER_LOGS=1`. However, this isn't the most discoverable, as both Erik and vdh asked me how to get server logs from Complement in the same day. It would be better if: - we always printed server logs, - to disk, - based on the hs name, - and then removed `COMPLEMENT_ALWAYS_PRINT_SERVER_LOGS`. For extra discoverability, indicating that server logs are going to file X would be useful. This would be a breaking change to the Complement API.