Notify once when a heavily used limit resets back to empty, porting the
macOS weekly-limit reset detector to the widget's data model. A usage row
arms at the 80% warning level and fires a single low-urgency notification
when it drops back to the reset floor, so routine short-window resets stay
quiet. Gated by a new notifyLimitResets toggle (default on).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>