feat: add NativeWind support and update documentation

[EQuimper]

feat: add react-native-ease/nativewind entry point

Summary

• Add react-native-ease/nativewind convenience entry point that calls cssInterop(EaseView, { className: 'style' }) so NativeWind users can use className on EaseView with a single import
• Add nativewind >= 4 as an optional peer dependency
• Update the migration skill to auto-detect NativeWind and add the import during migrations
• Add README documentation for NativeWind setup

Changes

File	What
src/nativewind.ts	New entry point — registers EaseView with NativeWind's cssInterop
src/__tests__/nativewind.test.ts	Test verifying cssInterop is called correctly
package.json	Added ./nativewind export, optional nativewind peer dep
tsconfig.json	Added path alias for new entry point
README.md	NativeWind setup section with usage example
skills/.../SKILL.md	Migration skill now detects NativeWind and adds the import automatically

Usage

// Add once in app root
import 'react-native-ease/nativewind';

// Then className works
<EaseView className="flex-1 bg-white p-4" animate={{ opacity: 1 }} />