Clicking a stop (or the Edit link) in /admin/stops now opens a modal
with Details/Products/Message tabs instead of navigating to
/admin/stops/[id].
- Add getStopDetails server action (returns stop, brand, candidate
products, assigned products, brand list in one round trip).
- Add StopDetailModal component with tabbed panels that reuse the
existing StopEditForm, StopProductAssignment, and
MessageCustomersSection.
- Add an optional onSaved callback to StopEditForm so the modal can
refetch + router.refresh() after a save.
- StopTableClient now opens the modal on row click; the /admin/stops/[id]
route is kept in place for direct links/bookmarks.
