fix(store): reset and uniformly hydrate trip-scoped slices in loadTrip (H4, H5) (#1180)

loadTrip only replaced the first slice group, so budget/reservations/files
from a previous trip stayed visible after switching trips (data exposure on a
shared screen). Those three also loaded via separate tab-gated effects, so they
never hydrated offline for an unopened tab.

- resetTrip() clears every trip-scoped slice (keeps global tags/categories) and
  runs at the top of loadTrip, so a switch can't leak the prior trip's data
- loadTrip now hydrates budget/reservations/files through their repos alongside
  the rest (non-fatal catches), making offline hydration uniform
- useTripPlanner drops the redundant loadFiles + reservations/budget effects;
  tab-gated lazy reloads stay as on-demand refresh
- tests: cross-trip no-leak, uniform hydration, resetTrip

client/src/pages/tripPlanner/useTripPlanner.ts

@@ -221,11 +221,12 @@ export function useTripPlanner() {
     }
   }, [isLoading, places])
 
-  // Load trip + files (needed for place inspector file section)
+  // Load the trip. loadTrip hydrates every trip-scoped slice (days, places,
+  // packing, todo, budget, reservations, files) so offline hydration is uniform
+  // and there's no cross-trip bleed; members/accommodations load alongside.
   useEffect(() => {
     if (tripId) {
       tripActions.loadTrip(tripId).catch(() => { toast.error(t('trip.toast.loadError')); navigate('/dashboard') })
-      tripActions.loadFiles(tripId)
       loadAccommodations()
       if (!navigator.onLine) {
         offlineDb.tripMembers.where('tripId').equals(Number(tripId)).toArray()
@@ -240,13 +241,6 @@ export function useTripPlanner() {
     }
   }, [tripId])
 
-  useEffect(() => {
-    if (tripId) {
-      tripActions.loadReservations(tripId)
-      tripActions.loadBudgetItems?.(tripId)
-    }
-  }, [tripId])
-
   useTripWebSocket(tripId)
 
   const [mapCategoryFilter, setMapCategoryFilter] = useState<Set<string>>(new Set())