Fixes the marker vanishing on the last day of the week.

More than a day before the weekly reset, Claude labels it with a weekday and time ("Resets Sun 6:00 AM"). Inside the final 24 hours it switches to a countdown ("Resets in 21 hr 0 min"), which the previous version couldn't read, so the marker dropped off the weekly bar for the last day of each week.

The extension now reads the countdown too, and the marker stays put right up to the reset. The "Current session"bar shows the same countdown, so the extension keeps the marker on the weekly bars and off the session.