Add Fastlane Google Play releases and automatic internal drafts

[andre487]

Adds Google Play uploads for Message487 through Fastlane. The play_release lane uploads the signed AAB, matching R8 mapping and localized changelogs, defaulting to an internal draft. It supports offline dry_run:true and Google API validate_only:true, with argument and credential validation.

After a v* tag builds verified artifacts and publishes the GitHub Release, the release workflow uploads the same artifacts to Google Play using SUPPLY_JSON_KEY_DATA, scoped to that step. Release-check tags and manual workflow dispatch remain build-only. Manually creating a GitHub Release does not trigger this workflow. A Play upload failure leaves the already published GitHub Release available.

Validation:

• Signed 0.0.5 APK/AAB build, JVM tests, debug/release lint and signature verification passed.
• Offline dry run and ruby scripts/test-play-release.rb passed; regression checks are included in PR CI.
• Workflow YAML and git diff --check passed.
• Live validate_only:true authenticated successfully but Google rejected the AAB because versionCode 5 has already been used. No Play release was committed. The next upload needs a new versionCode and rebuilt artifacts.

Updated English and Russian release instructions. The repository Actions secret is configured; key contents are not included in the repository.