EAS: production builds fail on Sentry's upload, appVersionSource is unset, and an iOS failure stops the Android build on main #186

Context

Found while producing the first Android build (#185). Each of these stops or weakens a later build, and none blocks the preview APK.

1. production builds fail in Gradle. A release build runs Sentry's source map upload, which exits non-zero with no SENTRY_AUTH_TOKEN (run 41596720266). feat(eas): link the app to the EAS project so CI can build it #185 sets SENTRY_DISABLE_AUTO_UPLOAD for preview only.
2. cli.appVersionSource is unset in eas.json. eas-cli warns that it "will be required in the future". production has autoIncrement: true, so the choice between local and remote decides where build numbers live.
3. A push to main builds iOS first. eas-build.yml has no continue-on-error, so until Apple credentials exist a failing Build iOS is expected to stop Build Android too (from knowledge of eas-cli, not yet observed on main).

Ask

• Set SENTRY_AUTH_TOKEN in the project's EAS environment variables, or decide that production skips the upload for now.
• Set cli.appVersionSource.
• Decide whether every push to main should build both platforms. Each one spends EAS build quota; the Android preview build took 27m 54s.

Acceptance

• eas build --profile production --platform android --non-interactive reaches a signed artifact.
• The appVersionSource warning is gone.
• A push to main does not lose its Android build to an iOS failure.