refactor(platform): extract blurActiveElement to infrastructure module

- Centralize duplicated Platform.OS === 'web' blur logic across 16 components
- Add blurActiveElement utility to src/infrastructure/platform module
- Optimize MessageBubble and ImageSegment with React.memo custom comparators
- Add useMemo for computed values in MessageSegmentsRenderer
- Update DTO types with is_system_notice and notice_content fields
- Fix keyboard dismissal order in useChatScreen handleDismiss
- Simplify userStore follow/unfollow state updates
- Remove unnecessary TypeScript type assertions throughout codebase

src/screens/profile/AboutScreen.tsx

@@ -482,7 +482,6 @@ export const AboutScreen: React.FC = () => {
   const appInfoItems = [
     { key: 'name', icon: 'information-outline', title: '应用名称', value: APP_NAME },
     { key: 'version', icon: 'tag-outline', title: '版本号', value: `v${APP_VERSION} (${BUILD_NUMBER})` },
-    { key: 'developer', icon: 'office-building-outline', title: '开发者', value: '青春之旅电子信息科技' },
   ];
 
   const renderSettingItem = (item: { key: string; icon: string; title: string; value?: string; action?: () => void }, index: number, total: number, showArrow: boolean = false) => (