feat: snackbar notifications

[isekovanic]

🎯 Goal

This PR adds an SDK level snackbar/notification system and wires missing notification sources to the RN SDK. This is a feature that's been missing for some time.

🛠 Implementation details

• Adds notification rendering components:
  • NotificationList for positioning, filtering, target-panel routing, animation, timeout handling, and swipe-to-dismiss.
  • Notification for message, severity icon, optional actions, persistent close button, and accessibility roles.
  • NotificationIcon for default severity-based icons.
• Adds notification hooks/utilities:
  • useNotificationApi / useSystemNotifications / useNotifications / useNotificationTarget.
  • Target panel support for channel, thread, channel-list, and thread-list.
  • Incident-based notification type generation for consistent dedupe/analytics-friendly event names.
• Wires notifications into missing SDK flows:
  • message actions, channel list actions, poll ending, reaction fetch errors, unread jump errors, send/edit failures, attachment/command errors, and audio recording/playback errors.
• Adds customization points:
  • component overrides via ComponentsContext: NotificationList, Notification, NotificationIcon.
  • theme overrides via theme.notification and theme.notificationList.
  • NotificationList props for panel, fallbackPanel, filter, enterFrom, and verticalAlignment.
  • notification options for severity, duration, actions, metadata, tags, targetPanels, and type.
• Adds and validates translations for all supported locales.

TODOs:

• Actual notification UI and animations (this needs to be rethinked a bit and done in accordance to our design)

• General cleanup

• Think about removing notification list

  🧪 Testing

  • yarn lint
  • yarn test:typecheck
  • yarn test:unit --runInBand

  ☑️ Checklist

  • I have signed the Stream CLA (required)
  • PR targets the develop branch
  • Documentation is updated
  • New code is tested in main example apps, including all possible scenarios
    • SampleApp iOS and Android
    • Expo iOS and Android

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
js_bundle_size	364 KB	367 KB	+2660 B	🔴