lynx_view_platform_interface

A common platform interface for lynx_view. App developers should depend on lynx_view directly, not this package.

Defines LynxViewPlatform (implemented by lynx_view_android/lynx_view_ios) and the shared MethodChannelLynxView used by both — the AndroidView/UiKitView selection and per-instance MethodChannel plumbing live here once instead of being duplicated per platform.