Add a weekly + manual release-dryrun workflow that exercises the full store
pipeline without publishing: Android validates the AAB against Google Play
(validate_only), iOS builds a fully signed archive via match (readonly) and
skips the App Store upload. Both Fastlane lanes gain a dry_run option that
reuses the real release path so the dry-run stays faithful to it.
Also add release-mode compile checks (flutter build apk/ios --release) to CI
and PR checks to catch release-only breakage, pinning the JDK to match the
release toolchain. Trim ci.yml from a redundant 3-OS matrix to two
purpose-built jobs (analyze/test once on Linux, iOS build on macOS).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
