Add Tonuino Manager website and Sparkle updates

Sources/TonuinoManager/App/TonuinoManagerApp.swift

@@ -0,0 +1,35 @@
+import SwiftUI
+import Sparkle
+import AppKit
+
+final class AppDelegate: NSObject, NSApplicationDelegate {
+    static var updater: SPUStandardUpdaterController?
+    func applicationDidFinishLaunching(_ notification: Notification) {
+        guard let feed = Bundle.main.object(forInfoDictionaryKey: "SUFeedURL") as? String,
+              URL(string: feed)?.scheme != nil,
+              let key = Bundle.main.object(forInfoDictionaryKey: "SUPublicEDKey") as? String,
+              !key.isEmpty else { return }
+        Self.updater = SPUStandardUpdaterController(startingUpdater: true, updaterDelegate: nil, userDriverDelegate: nil)
+    }
+}
+
+@main
+struct TonuinoManagerApp: App {
+    @NSApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate
+    @StateObject private var model = AppModel()
+
+    var body: some Scene {
+        WindowGroup {
+            ContentView()
+                .environmentObject(model)
+                .frame(minWidth: 980, minHeight: 640)
+        }
+        .commands {
+            CommandGroup(replacing: .newItem) { }
+            CommandGroup(after: .appInfo) {
+                Button("Auf Updates prüfen…") { AppDelegate.updater?.checkForUpdates(nil) }
+                    .disabled(AppDelegate.updater?.updater.canCheckForUpdates != true)
+            }
+        }
+    }
+}