Initiales HabitTracker-Projekt: SwiftUI + SwiftData Gewohnheiten-Tracker

Natives iOS-App-Gerüst (Xcode 26, synchronisierte Ordner, iOS 18+).

Features:
- Gewohnheiten anlegen (Name, SF-Symbol, Farbe), heute abhaken, Streaks, Löschen
- Detailansicht mit Monatskalender (Tage nachtragbar) und Statistiken
- Tägliche Erinnerungen via lokale Notifications
- Home-Screen-Widget (klein/mittel) mit App-Group-Datenaustausch

HabitTracker/Views/HabitListView.swift

@@ -0,0 +1,69 @@
+import SwiftUI
+import SwiftData
+
+struct HabitListView: View {
+    @Environment(\.modelContext) private var context
+    @Environment(\.scenePhase) private var scenePhase
+    @Query(sort: \Habit.createdAt) private var habits: [Habit]
+    @State private var showingAdd = false
+
+    var body: some View {
+        NavigationStack {
+            Group {
+                if habits.isEmpty {
+                    ContentUnavailableView(
+                        "Keine Gewohnheiten",
+                        systemImage: "checklist",
+                        description: Text("Tippe auf +, um deine erste Gewohnheit anzulegen.")
+                    )
+                } else {
+                    List {
+                        ForEach(habits) { habit in
+                            NavigationLink {
+                                HabitDetailView(habit: habit)
+                            } label: {
+                                HabitRowView(habit: habit)
+                            }
+                        }
+                        .onDelete(perform: delete)
+                    }
+                }
+            }
+            .navigationTitle("Heute")
+            .toolbar {
+                ToolbarItem(placement: .topBarTrailing) {
+                    Button {
+                        showingAdd = true
+                    } label: {
+                        Label("Hinzufügen", systemImage: "plus")
+                    }
+                }
+            }
+            .sheet(isPresented: $showingAdd) {
+                AddHabitView()
+            }
+        }
+        .task {
+            WidgetSync.refresh(context)
+        }
+        .onChange(of: scenePhase) { _, phase in
+            if phase == .active {
+                WidgetSync.refresh(context)
+            }
+        }
+    }
+
+    private func delete(at offsets: IndexSet) {
+        for index in offsets {
+            let habit = habits[index]
+            NotificationManager.cancel(for: habit)
+            context.delete(habit)
+        }
+        WidgetSync.refresh(context)
+    }
+}
+
+#Preview {
+    HabitListView()
+        .modelContainer(for: [Habit.self, HabitEntry.self], inMemory: true)
+}