The debconf preseed parser interprets \n in string values as literal
newlines. The printf format string had its \n converted to real newlines
before the shell saw it, causing ExecStart= to be executed as a separate
command ("Illegal number: ExecStart="). Replace the single printf with
multiple echo statements that avoid \n entirely.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
