- #61: CNBottomSheet.showCupertino compile error on Flutter < 3.44
  (scrollableBuilder param window). Switched to builder: which compiles
  from Flutter 3.35 through master.
- #46 bug A: CNToast queue deadlock after route pop — store
  OverlayState instead of BuildContext on queued entries.
- #46 bug B: yellow double-underlines under MaterialApp — wrap toast
  content in Material(type: MaterialType.transparency) inside
  _ToastOverlay.build.
- New Testing demo screen reproducing both #46 bugs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>