versionName in android/app/build.gradle was stale at 0.4.1 while app.json /
package.json declare 0.4.2, so CI-built APKs reported the wrong version string.
Align it. Also adds context.md (goal/design/plan/progress) and ignores the
generated index.android.bundle artifact.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
