Qing liu/fix/timesheet integration

[QuinnieLiu]

Timesheet Page Integration:

• Wire Timesheet page to live shift and attendance APIs
• Fix date sort and update date format on Timesheet page

Timesheet Status Logic：

• Completed → present (both clockIn and clockOut recorded)
• Active → incomplete (clocked in, not yet out, within 5-min grace of scheduled start)
• Late → incomplete + clockIn > scheduledStart + 5min — frontend-only derivation, no backend equivalent
• Absent → absent (no clockIn recorded)