Run the daily wiki maintenance cycle: check all source freshness, update the index, and regenerate hot.md. Use this skill when the user says "/daily-update", "run the daily update", "update everything", "morning sync", "refresh the wiki index", or when triggered by the launchd cron at 9 AM. Also use to set up or verify the cron + terminal notification infrastructure for the first time ("set up the daily cron", "install the terminal notification", "how do I get the morning reminder?").