fix: ESM module compatibility for EAS builds

[tarikfp]

Summary

Fix ESM module compatibility issues that cause build failures during EAS builds.

Issues Fixed

Error 1: Cannot use import statement outside a module

Cannot use import statement outside a module

The voltra/build/server.js uses ESM syntax (import/export) but Node.js treats it as CommonJS because there's no package.json with "type": "module" in the build/ directory.

Error 2: Cannot find module 'voltra/server'

Error: Cannot find module 'voltra/server'
require() of ES Module .../voltra/build/server.js not supported.
Instead change the require of server.js to a dynamic import()

Static import of voltra/server in the plugin fails when compiled to CommonJS.

Fix

1. Added postprepare script to create build/package.json with {"type": "module"}
   • This survives expo-module rebuilds (unlike a static file that gets cleared)
   • Marks the build directory as ESM module
2. Changed static import to dynamic import in prerenderWidgetState function

Changes

• package.json - Added postprepare script to create ESM marker after builds
• plugin/src/features/ios/files/swift/prerender.ts - Dynamic import for ESM compatibility

Checklist

• Follows conventional commits
• Backwards compatible
• No breaking changes
• Survives expo-module rebuild cycles

[vercel]

@tarikfp is attempting to deploy a commit to the Callstack Team on Vercel.

A member of the Team first needs to authorize it.

[V3RON]

Please split the pull request into two: one for the target name and a second for the ESM. The first change introduces a new feature, the second is a fix. They should live as separate commits on the main branch.

[V3RON]

There is one issue: when you build your module using the expo-module CLI, the build directory is cleared, so the package.json is removed. Eventually, I plan to extract the renderer into a separate package, but for now, I believe we can use a post-prepare hook to recreate this package.json.

"postprepare": "echo '{\"type\": \"module\"}' > build/package.json",

[tarikfp]

There is one issue: when you build your module using the expo-module CLI, the build directory is cleared, so the package.json is removed. Eventually, I plan to extract the renderer into a separate package, but for now, I believe we can use a post-prepare hook to recreate this package.json.

"postprepare": "echo '{\"type\": \"module\"}' > build/package.json",

Right, updated the PR. voltra/server issue has an ugly fix for now, but extraction would be good if it's already planned 👍🏻