[chrfalch]

Summary

React Native plans to make Swift Package Manager the default iOS dependency setup in 0.89, with CocoaPods as an opt-out. Today init always sets up a new app with CocoaPods, so a new app does not get the default.

This PR changes init on macOS, for React Native 0.87 and later:

1. After dependencies are installed, init runs React Native's own setup script: setup-apple-spm add --deintegrate --yes. It removes the template's CocoaPods setup and adds the Swift Package Manager setup. The pod install step and its prompt do not run.
2. A new flag, --skip-spm, keeps the CocoaPods setup. --install-pods then works as before.
3. --install-pods true without --skip-spm is an error where the setup would run, so scripts see the conflict instead of a silent change.
4. If the setup fails, init prints a warning and the command to retry, and finishes. This is the same as a failed pod install today.
5. With --skip-install, init prints the setup command to run later.

Nothing changes on Linux or Windows, or for React Native 0.86 and earlier. With --template or an out-of-tree --platform-name, init does not know the React Native version up front: --install-pods true keeps CocoaPods there, and otherwise the setup runs if the installed React Native has the script.

run-ios and build-ios already detect a Swift Package Manager project (#2858), so they work on the new app without a Podfile install.

Depends on: react/react-native#59368 (spm deinit, the way back to CocoaPods for an existing app). This PR is a draft until that lands. The code does not call deinit.

Test Plan

Unit tests:

yarn jest packages/cli/src/commands/init

Result: 7 suites, 96 tests pass. New: __tests__/spm.test.ts, __tests__/init.test.ts (through initialize), __tests__/printRunInstructions.test.ts. yarn lint and yarn build:ts pass.

End-to-end, with a local build of this branch, Xcode 27.1, CocoaPods 1.16.2:

Case	Result
init on RN 0.88.1	Swift Package Manager set up, no CocoaPods references left, no pod text, simulator build succeeds
init on RN 0.87.1	same
init --skip-spm	CocoaPods setup kept, pod instructions printed
init --install-pods true	exits 1 before the project folder is made
init with no pod on PATH	warning and retry command, project left on CocoaPods

Not tested: React Native 0.89 (not released).

Checklist

• Documentation is up to date.
• Follows commit message convention described in CONTRIBUTING.md.
• For functional changes, my test plan has linked these CLI changes into a local react-native checkout (instructions). Tested with a local CLI build on fresh apps from released React Native versions instead.