firebase_messaging_watchos 0.0.1-beta.1

watchOS implementation of firebase_messaging, bridging the Firebase Apple SDK (FirebaseMessaging) over dart:ffi for tokens, topics, and messages.

0.0.1-beta.1

• Initial watchOS implementation of firebase_messaging: a dart:ffi bridge over the Firebase Apple SDK (FirebaseMessaging) implementing tokens (getToken, getAPNSToken, deleteToken, onTokenRefresh), permissions (requestPermission, getNotificationSettings mapped to the watchOS-safe UNNotificationSettings subset), messages (onMessage, onMessageOpenedApp, getInitialMessage), topics (subscribeToTopic/unsubscribeFromTopic), and presentation/auto-init configuration.
• Receives the APNs device token and notification payloads through the flutter-watchos runner's FlutterWatchOSAppDelegate (@WKApplicationDelegateAdaptor), the only path watchOS exposes for remote notifications.
• registerBackgroundMessageHandler is a no-op (watchOS has no background isolate); setDeliveryMetricsExportToBigQuery is Android/web only.
• Scaffolded with flutter-watchos plugin port, then hand-finished.
• Links the Firebase Apple SDK via the CLI's external-SwiftPM-dependency support. Verified on the watch simulator: host unit tests (15/15) and an on-simulator smoke test. Not yet verified on physical watch hardware; published as a pre-release.