Tasks App: Parent-Child Inventory for Next Check-in Calculation

Currently, the Tasks app calculates the 'next check-in' for turnover tasks based only on the specific listing assigned to the task. For listings using a parent-child setup, this means a turnover for a child unit may not account for an earlier reservation on the parent listing that also occupies that unit.

As a result, a same-day turnover can appear as though the cleaner has several days to complete it. For example, the app may show that the next check-in is five days away even though a guest checking into the parent listing will occupy the unit later that same day. This could easily cause a missed or delayed turnover.

The requested improvement is for the Tasks app to calculate the next check-in by considering reservations from both the child listing and its parent listing (and vice versa), ensuring scheduling is aligned with Hospitable's parent-child inventory handling.