tui-cs/Terminal.Gui ? reverse-engineered prompt

Build me a cross platform terminal UI toolkit for .NET that lets me make polished console apps with a real interface, not just text output.

I want it to work on Windows, macOS, and Linux, and make it easy to build things like windows, menus, forms, tables, trees, editors, progress bars, charts, file pickers, and wizards. It should feel keyboard friendly, support the mouse too, handle Unicode and color well, and have a clean layout system so the UI can resize nicely in the terminal.

Please include a simple getting started example, a sample app that shows off the different controls, and good documentation so someone can learn how to use it quickly. If there are modern .NET patterns or current docs I should follow, look them up online if needed.