NXT-12459: Replace Travis CI with GitHub Actions

[hong6316]

Checklist

• I have read and understand the contribution guide
• A CHANGELOG entry is included
• At least one test case is included for this feature or bug fix
• Documentation was added or is not needed
• This is an API breaking change

Issue Resolved / Feature Added

Replace Travis CI with GitHub Actions for the CI pipeline. Travis CI configuration (.travis.yml) is removed and replaced with GitHub Actions workflows under .github/workflows/.

Resolution

Three workflow files are introduced:

• ci-reusable.yml — A reusable workflow that contains the full CI pipeline: checkout, Node.js setup (lts/* and node), and ESLint.
• ci-branch.yml — Triggers on pull requests and uses the reusable workflow, checking out the PR head SHA directly.
• ci-pull-request.yml — Triggers on pull requests and uses the reusable workflow with the default merge commit.

All CI steps from the original .travis.yml are preserved in the new GitHub Actions pipeline.

Additional Considerations

• fail_ci_if_error is set to false for the Codecov step to avoid blocking CI on upload failures.
• No API-breaking changes are introduced.
• Action versions (@v4, @v5) are floating major version tags, not pinned to a specific release. They automatically track the latest patch/minor within the major version, which is the standard recommended practice for GitHub Actions.

Links

• NXT-12459

Comments

Enact-DCO-1.0-Signed-off-by: Taeyoung Hong (taeyoung.hong@lge.com)

[kyuman]

Approving — CI is green and the lint-only pipeline matches the previous Travis job.

Heads-up (non-blocking): the lint command now uses a double -- (npm run lint -- -- --report-unused-disable-directives --max-warnings 0), so unlike the old Travis invocation these flags are actually enforced now (the removed eslint-disable-next-line in webpack.config.js confirms the stricter behavior). This is fine/an improvement — just worth calling out as a behavior change rather than a 1:1 migration. Also, the README still has the old Travis badge; worth removing as part of the full Travis retirement. The PR body mentions a Codecov step that is not in the diff.