Replace WebSocket-based real-time communication with Server-Sent Events (SSE) across the messaging infrastructure. This includes:
- Create new SSEClient datasource to manage SSE connections
- Create new SSEMessageHandler to process SSE events
- Update ProcessMessageUseCase to use SSEClient instead of WebSocketClient
- Update MessageManager and MessageStateManager to work with SSE handlers
- Rename connection state variables from `isWebSocketConnected` to `isSSEConnected`
- Update type definitions in dto.ts (WSEventType → SSEEventType, etc.)
- Delete obsolete WebSocketClient and WebSocketMessageHandler files
- Update comments and documentation to reflect SSE terminology
This refactoring aligns with the backend's SSE implementation for better compatibility with React Native's networking capabilities.
Add new ScheduleTab to main navigation with ScheduleStackNavigator for managing course schedule screens. Includes CourseDetailScreen with modal presentation. Also exports scheduleService and related types for the new schedule feature.
fix(message): add group_id parameter to invite and request handlers
Pass group_id from extra_data when calling respondInvite and reviewJoinRequest APIs, as the backend now requires this parameter.
refactor(message): extract mergeMessagesById helper method
Centralize message merging logic into a reusable private method to avoid duplication and ensure consistent message deduplication behavior.
