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

Shared/Shared.swift

@@ -0,0 +1,61 @@
+import SwiftUI
+
+// MARK: - Snapshot shared between app and widget
+
+struct WidgetSnapshot: Codable {
+    struct Item: Codable, Identifiable {
+        var id: UUID
+        var name: String
+        var symbolName: String
+        var colorHex: String
+        var isDoneToday: Bool
+    }
+
+    var generatedAt: Date
+    var items: [Item]
+
+    static let empty = WidgetSnapshot(generatedAt: .now, items: [])
+}
+
+// MARK: - App Group backed store
+
+enum SharedStore {
+    static let appGroupID = "group.de.motocamp.HabitTracker"
+    private static let key = "widgetSnapshot"
+
+    private static var defaults: UserDefaults? {
+        UserDefaults(suiteName: appGroupID)
+    }
+
+    static func save(_ snapshot: WidgetSnapshot) {
+        guard let data = try? JSONEncoder().encode(snapshot) else { return }
+        defaults?.set(data, forKey: key)
+    }
+
+    static func load() -> WidgetSnapshot {
+        guard let data = defaults?.data(forKey: key),
+              let snapshot = try? JSONDecoder().decode(WidgetSnapshot.self, from: data)
+        else { return .empty }
+        return snapshot
+    }
+}
+
+// MARK: - Color from hex (used by both targets)
+
+extension Color {
+    /// Creates a color from a "#RRGGBB" hex string. Falls back to system green on bad input.
+    init(hex: String) {
+        let cleaned = hex.trimmingCharacters(in: CharacterSet(charactersIn: "#"))
+        var value: UInt64 = 0
+        Scanner(string: cleaned).scanHexInt64(&value)
+
+        if cleaned.count == 6 {
+            let r = Double((value >> 16) & 0xFF) / 255
+            let g = Double((value >> 8) & 0xFF) / 255
+            let b = Double(value & 0xFF) / 255
+            self.init(.sRGB, red: r, green: g, blue: b)
+        } else {
+            self.init(.sRGB, red: 52 / 255, green: 199 / 255, blue: 89 / 255)
+        }
+    }
+}