HTTP CRUD operations, WebSocket real-time communication, authentication, and performance optimization for Flutter apps.

• Covers all HTTP methods (GET, POST, PUT, DELETE) with JSON serialization, plus WebSocket connections for real-time data
• Includes authentication patterns (Bearer tokens, Basic Auth, API keys) and comprehensive error handling by status code
• Provides background JSON parsing with isolates to prevent UI blocking on large responses, plus retry logic with exponential backoff
• Demonstrates repository and service layer patterns for clean architecture integration, with caching and single source of truth patterns