Introduce a GroceryListManager facade that delegates to either the existing
in-app GroceryList or a new RemindersGroceryStore backed by EventKit. Users
choose the mode in Settings; when Reminders mode is active the Grocery List
tab is hidden. Recipe-to-reminder grouping uses a local mapping file
(reminder_mappings.data) instead of polluting the reminder's notes field,
with automatic pruning when reminders are deleted externally.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Adopt modern SwiftUI patterns now that the minimum target is iOS 18:
NavigationStack, .toolbar, .tint, new Tab API with sidebarAdaptable
style, and remove iOS 17 availability checks. Add Liquid Glass effect
support for iOS 26 in TimerView and fix an optional interpolation
warning in AppState.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
