availableStyles constant 
    
      
      
      
  Implementation
  static const List<BubbleStyleConfig> availableStyles = [
  BubbleStyleConfig(
    name: MessageBubbleBuilder.styleNormal,
    description: '标准圆角气泡',
    icon: Icons.chat_bubble_outline,
  ),
  BubbleStyleConfig(
    name: MessageBubbleBuilder.styleDachshund,
    description: '腊肠狗样式气泡',
    icon: Icons.pets,
  ),
  BubbleStyleConfig(
    name: MessageBubbleBuilder.styleCup,
    description: '咖啡杯样式气泡',
    icon: Icons.coffee,
  ),
  BubbleStyleConfig(
    name: MessageBubbleBuilder.styleMinimal,
    description: '极简样式',
    icon: Icons.horizontal_rule,
  ),
];