fix: downgrade react-native to 0.79.7 for Expo SDK 53 compatibility

Expo SDK 53 ships with React Native 0.79.x which pulls metro ~0.82.
metro 0.82+ still exports ./src/* in its package.json exports field,
which @expo/cli v0.24 requires. metro 0.84 removed this export,
breaking expo export (ERR_PACKAGE_PATH_NOT_EXPORTED).

Also removes stale patch scripts (patch-metro-exports.js, check-metro.js)
that are no longer needed with the compatible metro version.

Author: Chidubemkingsley