feat: add support for react 19

[duyhungtnn]

This pull request updates the project to add support for React 19 in both the codebase and CI workflows, while also clarifying peer dependency requirements and supported versions in the documentation. The changes ensure that end-to-end (E2E) tests are run against both React 18 and React 19 environments for iOS and Android, and the documentation now reflects the expanded compatibility and installation steps.

CI Workflow Updates for React 19 Support:

• The E2E GitHub Actions workflow (.github/workflows/e2e.yml) now runs tests for both React 18 and React 19 by introducing a matrix strategy for the react-version parameter in both iOS and Android jobs. This includes environment setup, dependency caching, and separate build/test steps for each React version. [1] [2] [3] [4] [5] [6]
• The workflow trigger branch was updated from feat/init-sdk to feat/support-react-19 to align with the new feature branch naming.
• The web build workflow (.github/workflows/build.yml) was updated to build and export both demo/expo_react_18 and demo/expo_react_19 projects for the web platform.

Documentation Improvements:

• The README.md now lists @bucketeer/js-client-sdk and @bucketeer/react-client-sdk as required peer dependencies and clarifies installation instructions.
• The supported React and React Native versions are updated to explicitly include React 19 and React Native 0.79.0+, and clarify the status of earlier versions.

E2e tests passed
https://github.com/bucketeer-io/react-native-client-sdk/actions/runs/19662569026

[Copilot]

Pull request overview

This pull request adds React 19 support to the react-native-client-sdk while maintaining React 18 compatibility. The changes introduce a matrix testing strategy in CI workflows to test both React versions, create separate demo projects for each React version, update peer dependencies to support both versions, and clarify documentation about supported versions and installation requirements.

Key changes:

• CI workflows now test both React 18 and React 19 through matrix strategies
• New demo projects: demo/expo_react_19 and demo/expo_react_18 (previously example)
• Peer dependencies updated to support React 18.2.0 through 19.x
• SDK dependencies moved to devDependencies and added as peer dependencies

Reviewed changes

Copilot reviewed 69 out of 182 changed files in this pull request and generated no comments.

File	Description
package.json	Updated scripts for separate React version testing, moved SDK dependencies to devDependencies, added peer dependency requirements, changed workspace paths
yarn.lock	Added React 19, Expo 54, and related dependency versions while maintaining React 18 dependencies
e2e/react_versions/*.yml	New E2E test files to verify React version-specific functionality
demo/expo_react_19/*	Complete new demo project for React 19 testing with Expo 54 and React Native 0.81

Files not reviewed (1)

• demo/expo_react_19/ios/example.xcworkspace/contents.xcworkspacedata: Language not supported

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[duyhungtnn]

@cre8ivejp please help me to take a look

[cre8ivejp]

Nice work 🎉