style(community): DynamicNewsCard 标题样式微调

- 移除 Heading 组件，简化为 HStack + Text
  - 调整图标和文字大小

src/views/Community/components/DynamicNews/DynamicNewsCard.js

@@ -641,12 +641,10 @@ const [currentMode, setCurrentMode] = useState('vertical');
           <Flex justify="space-between" align="center">
             {/* 左侧：标题 + 模式切换按钮 */}
             <HStack spacing={4}>
-              <Heading size={isMobile ? "sm" : "md"} color={PROFESSIONAL_COLORS.text.primary}>
               <HStack spacing={2}>
-                  <Clock size={20} color={PROFESSIONAL_COLORS.gold[500]} />
-                  <Text bgGradient={PROFESSIONAL_COLORS.gradients.gold} bgClip="text">实时要闻·动态追踪</Text>
+                <Clock size={18} color={PROFESSIONAL_COLORS.gold[500]} />
+                <Text fontSize={isMobile ? "md" : "lg"} fontWeight="bold" bgGradient={PROFESSIONAL_COLORS.gradients.gold} bgClip="text">实时要闻·动态追踪</Text>
               </HStack>
-              </Heading>
               {/* 模式切换按钮（移动端隐藏） */}
               {!isMobile && <ModeToggleButtons mode={mode} onModeChange={handleModeToggle} />}
             </HStack>