Add POI category filters, delete item button, and fix itinerary persistence

- Expand POI categories from 5 to 7 (restaurant, bar, coffee, hotel, parking, attraction, entertainment)
- Add category filter chips with per-category API calls and caching
- Add delete button with confirmation dialog to Edit Item sheet
- Fix itinerary items not persisting: use LocalItineraryItem (SwiftData) as primary store with CloudKit sync as secondary, register model in schema

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

SportsTime/SportsTimeApp.swift

@@ -46,6 +46,7 @@ struct SportsTimeApp: App {
             // User data models
             SavedTrip.self,
             TripVote.self,
+            LocalItineraryItem.self,
             UserPreferences.self,
             CachedSchedule.self,
             // Stadium progress models