fix(macos-init): add --legacy-peer-deps to npm install command

[ludwig-pro]

Summary

This PR fixes the installation failure when running npx react-native-macos-init on projects with newer patch versions of React Native.

Problem

When following the official Getting Started guide:

npx @react-native-community/cli init myProject --version 0.79
cd myProject
npx react-native-macos-init

The last command fails with:

Command failed: npm install --save --silent "react-native-macos@^0.79.0-0"

Root Cause

1. The published react-native-macos@0.79.1 declares an exact peer dependency: "react-native": "0.79.6"
2. The React Native CLI installs the latest patch version (e.g., react-native@0.79.7)
3. npm 7+ enforces strict peer dependency checking by default
4. npm refuses to install due to the version mismatch (0.79.6 vs 0.79.7)
5. The --silent flag hides the actual error message, making debugging difficult

Solution

Add --legacy-peer-deps to the npm install command. This flag:

• Makes npm behave like npm 6, ignoring peer dependency version mismatches
• Is safe for patch version differences (0.79.x) which are backward-compatible by semver convention
• Does not create duplicate installations of react-native

Changes

• packages/react-native-macos-init/src/cli.ts: Added --legacy-peer-deps flag to the npm install command

Test Plan

1. Create a new React Native project: npx @react-native-community/cli init TestApp --version 0.79
2. Verify that react-native@0.79.7 (or newer patch) is installed
3. Run npx react-native-macos-init with this fix
4. Confirm installation succeeds without errors

Related

I'll open a separate issue to discuss using a caret range (^0.79.0) instead of exact versions for the react-native peer dependency in release branches.

[Saadnajmi]

Sorry for the delay! We were working very hard on getting 0.81 out the door and I hadn't looked at other PRs.

The strict peer dep is intentional, it's what we use to determine the right version of Hermes to use. So I'm not sure I want to take this fix but also I need to think about what we need to do to our unit flow to fix 🤔