Reservation toggle, todo/packing toggle and budget reorder were swallowing API errors after rolling back, so the user saw the change silently snap back with no explanation. Route those failures through the existing toast channel (new store/notify.ts bridges to window.__addToast, the same channel SystemNoticeBanner uses); the reservation toggle re-throws so ReservationsPanel's own translated toast finally fires. Also wire the existing parseInDev/checkInDev response validation into the maps and notification-test endpoints to catch contract drift in dev.
Add entity/response Zod schemas to @trek/shared (place, trip, assignment, day, budget, packing, reservation), each matched against the producing server service, and re-export them from client types.ts instead of the hand-written duplicates that had drifted (name/title, amount/total_price, owner_id/user_id, cover_url/cover_image, ...). Updates the call sites and test fixtures the corrected types surfaced; type-only, no runtime behaviour change.
Maurice