Add meal plan feature with cross-device sync and automatic stale data cleanup

Introduces weekly meal planning with a calendar-based tab view, per-recipe
date assignments synced via Nextcloud Cookbook custom metadata, and 30-day
automatic pruning of old entries on load, save, and sync merge.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Nextcloud Cookbook iOS Client/Views/MainView.swift

@@ -10,6 +10,7 @@ import SwiftUI
 struct MainView: View {
     @StateObject var appState = AppState()
     @StateObject var groceryList = GroceryListManager()
+    @StateObject var mealPlan = MealPlanManager()
 
     // Tab ViewModels
     @StateObject var recipeViewModel = RecipeTabView.ViewModel()
@@ -20,7 +21,7 @@ struct MainView: View {
     @State private var selectedTab: Tab = .recipes
 
     enum Tab {
-        case recipes, search, groceryList
+        case recipes, search, mealPlan, groceryList
     }
 
     var body: some View {
@@ -30,6 +31,7 @@ struct MainView: View {
                     .environmentObject(recipeViewModel)
                     .environmentObject(appState)
                     .environmentObject(groceryList)
+                    .environmentObject(mealPlan)
             }
 
             SwiftUI.Tab("Search", systemImage: "magnifyingglass", value: .search, role: .search) {
@@ -37,6 +39,14 @@ struct MainView: View {
                     .environmentObject(searchViewModel)
                     .environmentObject(appState)
                     .environmentObject(groceryList)
+                    .environmentObject(mealPlan)
+            }
+
+            SwiftUI.Tab("Meal Plan", systemImage: "calendar", value: .mealPlan) {
+                MealPlanTabView()
+                    .environmentObject(mealPlan)
+                    .environmentObject(appState)
+                    .environmentObject(groceryList)
             }
 
             if userSettings.groceryListMode != GroceryListMode.appleReminders.rawValue {
@@ -85,6 +95,11 @@ struct MainView: View {
             if UserSettings.shared.grocerySyncEnabled {
                 await groceryList.syncManager?.performInitialSync()
             }
+            await mealPlan.load()
+            mealPlan.configureSyncManager(appState: appState)
+            if UserSettings.shared.mealPlanSyncEnabled {
+                await mealPlan.syncManager?.performInitialSync()
+            }
             recipeViewModel.presentLoadingIndicator = false
         }
     }