Add Sparkle update framework for macOS

Shared/YatteeApp.swift

@@ -5,6 +5,7 @@ import SwiftUI
 struct YatteeApp: App {
     #if os(macOS)
         @NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
+        @StateObject private var updater = UpdaterModel()
     #endif
 
     @StateObject private var menu = MenuModel()
@@ -18,7 +19,16 @@ struct YatteeApp: App {
         .handlesExternalEvents(matching: Set(["*"]))
         .commands {
             SidebarCommands()
+
             CommandGroup(replacing: .newItem, addition: {})
+
+            #if os(macOS)
+                CommandGroup(after: .appInfo) {
+                    CheckForUpdatesView()
+                        .environmentObject(updater)
+                }
+            #endif
+
             MenuCommands(model: Binding<MenuModel>(get: { menu }, set: { _ in }))
         }
         #endif
@@ -28,6 +38,7 @@ struct YatteeApp: App {
                 SettingsView()
                     .environmentObject(AccountsModel())
                     .environmentObject(InstancesModel())
+                    .environmentObject(updater)
             }
         #endif
     }