sdlc-rn-platform-specific

iOS / Android platform-specific code in React Native: Platform.OS, Platform.select, .ios.tsx / .android.tsx file extensions, native modules, permissions, safe area handling, status bar. Use this skill to: - Branch code at runtime via Platform.OS / Platform.select. - Use file extensions for whole-component swaps. - Link and use native modules (Expo SDK or autolinked bare). - Handle permissions across platforms. - Configure status bar and safe area correctly. Do NOT use this skill for: - General project structure (see rn-conventions). - Navigation (see rn-navigation). - Storage (see rn-state-and-storage). - Testing (see rn-testing).