feat: integrate Firebase Cloud Messaging for push notifications and consent management

[Apoll011]

Description

Summary

Integrates Firebase Cloud Messaging (FCM) into the Hosanna Mobile App to support push notifications, token lifecycle tracking tied to user sessions, and localized messaging. In addition, introduces a permission consent prompt, foreground message listeners for in-app delivery, and tap-action routing.

Changes

• Firebase Cloud Messaging & Session Management:

  • Integrated FCM for remote push notification delivery across mobile devices.
  • Linked device FCM token registration and invalidation to user authentication sessions.

• Permission & Consent UI:

  • Implemented notification permission request flows with a custom UI consent prompt.
  • Managed permission state tracking to handle user approvals and denials gracefully.

• Notification Handling & In-App Routing:

  • Added foreground message listeners to display incoming notifications while the app is active.
  • Implemented notification tap handlers to route users directly to relevant content upon interaction.

• Localization & Maintenance:

  • Added localization support for notification titles, bodies, and consent UI dialogs.
  • Bumped mobile app version to 1.2.0 in pubspec.yaml.

Performance / UX

• Contextual permission prompt informs users of notification benefits before triggering native OS permission dialogs.
• Foreground notification banners provide non-intrusive feedback for real-time team updates while using the app.

Technical Details

• FCM token registration is dispatched upon login and refreshed whenever tokens rotate, ensuring reliable notification delivery per user and organization.
• Tap handlers extract payload metadata to trigger internal app navigation.

Notes

• Requires Firebase configuration files (google-services.json / GoogleService-Info.plist) for local mobile build environments.
• Version bumped to 1.2.0 in pubspec.yaml.