dotnet/maui-samples — reverse-engineered prompt

Build me a .NET MAUI samples repo that feels like a learning kit and demo collection for cross platform apps made with C# and XAML. I want one shared codebase approach that can target Android, iOS, iPadOS, macOS, and Windows.

Please include a mix of runnable examples that cover the basics and a few more realistic apps, like a calculator, weather app, task app for beginners, navigation samples, a point of sale style app, and a simple AI chat sample, plus a version that can call tools. Organize it so the current stable samples are separate from preview only samples, and clearly mark any older content as deprecated. Also include guidance for people moving from Xamarin.Forms to .NET MAUI.

Make it easy to browse, open, and run each sample, with short explanations of what each one is showing and when to use it. If you need details, look up the current .NET MAUI docs online.