Move samples to dedicated repository

Samples are now in https://github.com/open-maui/maui-linux-samples

This keeps the framework repo focused and allows samples to:
- Reference NuGet package (real-world usage)
- Be cloned independently
- Have their own release cycle

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

samples/TodoApp/NewTodoPage.xaml.cs

@@ -1,31 +0,0 @@
-// NewTodoPage - Create a new todo item
-
-using Microsoft.Maui.Controls;
-using Microsoft.Maui.Graphics;
-
-namespace TodoApp;
-
-public partial class NewTodoPage : ContentPage
-{
-    private readonly TodoService _service = TodoService.Instance;
-
-    public NewTodoPage()
-    {
-        InitializeComponent();
-    }
-
-    private async void OnSaveClicked(object? sender, EventArgs e)
-    {
-        var title = TitleEntry.Text?.Trim();
-
-        if (string.IsNullOrEmpty(title))
-        {
-            TitleEntry.Placeholder = "Title is required!";
-            TitleEntry.PlaceholderColor = Colors.Red;
-            return;
-        }
-
-        _service.AddTodo(title, NotesEditor.Text ?? "");
-        await Navigation.PopAsync();
-    }
-}