The coach rhythm and the quiet hours both parse "HH:MM" wall-clock times
and each defined its own ClockTimeSchema, which the contracts index cannot
export twice. Both now import it from one module.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MRtGG9ARfqqhma3t85Ro2u
