README Usage Verification

Verifies the primary usage example in the project README.

This example exists as a documentation regression test. It ensures that the very first code snippet a user sees actually works.

Usage

RatatuiRuby.run do |tui|
  loop do
    tui.draw do |frame|
      frame.render_widget(
        tui.paragraph(
          text: "Hello, Ratatui! Press 'q' to quit.",
          alignment: :center,
          block: tui.block(
            title: "My Ruby TUI App",
            borders: [:all],
            border_color: "cyan"
          )
        ),
        frame.area
      )
    end
    case tui.poll_event
    in { type: :key, code: "q" } | { type: :key, code: "c", modifiers: ["ctrl"] }
      break
    else
      nil
    end
  end
end