feat: Upgrade React Native binding to 1.13.1

[Leeeon233]

Summary

• Upgrade the React Native package and Rust shim to 1.13.1.
• Use the published loro-ffi 1.13.1 crate.
• Regenerate UniFFI React Native TypeScript/native bridge output, including ensureMergeable* APIs.

Validation

• cargo check --manifest-path loro-rs/Cargo.toml
• yarn install
• yarn ubrn:android
• yarn ubrn:ios
• yarn typecheck
• yarn prepare
• yarn jest --runInBand --passWithNoTests

Notes

• yarn lint is still blocked because the package currently does not provide an eslint binary.