Note

Low Risk
Primarily a coordinated version/release bump across Flutter, Android, iOS/macOS, and web with updated dependency versions and minimum SDK constraints; no functional logic changes beyond version metadata.

Overview
Bumps the Flutter SDK release from 9.15.1 to 9.16.0 across package metadata (.version, pubspec.yaml, podspecs, Gradle files) and updates the embedded plugin version constants for Android/iOS/web.

Updates release documentation (CHANGELOG-LATEST.md, CHANGELOG.md, VERSIONS.md) to include the 9.16.0 notes, including the lowered minimum Flutter/Dart requirements and the purchases-hybrid-common bump to 17.54.0 (with corresponding native iOS/Android version references). Also updates purchases_ui_flutter to depend on purchases_flutter ^9.16.0.

^{Written by Cursor Bugbot for commit c93cfb2. This will update automatically on new commits. Configure here.}