Add mobile release preflight workflow

[bigdestiny2]

Summary

• add a macOS GitHub Actions workflow that reproduces mobile/native release preflight setup from a cold checkout
• generate native worklet bundles, mirror iOS BareKit/addon frameworks, mirror Android BareKit as an AAR, and upload the soft preflight JSON report
• add a report verifier so CI fails on new structural blockers while allowing only the known production credential/store blockers

Validation

• npm ci
• npm test
• npm audit --audit-level=high
• npm run bundle-all-native
• npm run barekit:fetch:addons
• npm run barekit:fetch:android
• npm run --silent release:preflight -- --json --soft > dist/release-preflight/mobile-release-preflight.json
• npm run check:release-preflight-report -- dist/release-preflight/mobile-release-preflight.json --allow-production-blockers
• node --test test/release-preflight.test.js test/release-preflight-report.test.js
• node --check scripts/fetch-android-barekit.js scripts/check-release-preflight-report.js scripts/fetch-barekit-addons.js
• git diff --check