Stub out goToNextUnread for SceneModel

Multiplatform/Shared/Article/ArticleToolbarModifier.swift

@@ -72,6 +72,7 @@ struct ArticleToolbarModifier: ViewModifier {
 				
 				ToolbarItem(placement: .bottomBar) {
 					Button {
+						sceneModel.goToNextUnread()
 					} label: {
 						AppAssets.nextUnreadArticleImage.font(.title3)
 					}

Multiplatform/Shared/SceneModel.swift

@@ -51,6 +51,13 @@ final class SceneModel: ObservableObject {
 		subscribeToToolbarChangeEvents()
 	}
 	
+	// MARK: Navigation API
+	
+	/// Goes to the next unread item found in Sidebar and Timeline order, top to bottom
+	func goToNextUnread() {
+		
+	}
+	
 	// MARK: Article Management API
 	
 	/// Marks all the articles in the Timeline as read

Multiplatform/Shared/SceneNavigationView.swift

@@ -108,6 +108,7 @@ struct SceneNavigationView: View {
 			}
 			ToolbarItem {
 				Button {
+					sceneModel.goToNextUnread()
 				} label: {
 					AppAssets.nextUnreadArticleImage
 				}