Show HN: Shirei, cross-platform GUI framework in native Go

# Summary Shirei is a cross-platform GUI framework for Go that allows developers to write user interfaces natively in Go rather than HTML and JavaScript, with identical output across macOS, Windows, and Linux. The framework uses an immediate-mode API approach where the UI is rebuilt each frame based on current data, eliminating the need to manually track widget states, and requires no external dependencies on Linux.