Feature request: Checklist staleness reminder with configurable threshold

[aabhinavvvvvvv]

Summary

Add an optional alert to notify users when a project's reproducibility checklist hasn't been reviewed in a configurable number of days.

Motivation

Users may forget to revisit their checklist as a project evolves. A staleness reminder would help keep reproducibility documentation up to date without being intrusive.

Proposed Behavior

• Track the last time any checklist item was updated
• If the checklist hasn't been touched in X days (configurable by the user), show an alert/banner on the project page
• Opt-in via user settings — disabled by default so it doesn't affect users who prefer a different workflow

[lrasmus]

Thank you so much for this suggestion, @aabhinavvvvvvv! I will review this with the rest of the team.