feat: 实现 Redux 全局状态管理事件关注功能

本次提交实现了滚动列表和事件详情的关注按钮状态同步：

✅ Redux 状态管理
- communityDataSlice.js: 添加 eventFollowStatus state
- 新增 toggleEventFollow AsyncThunk（复用 EventList.js 逻辑）
- 新增 setEventFollowStatus reducer 和 selectEventFollowStatus selector

✅ 组件集成
- DynamicNewsCard.js: 从 Redux 读取关注状态并传递给子组件
- EventScrollList.js: 接收并传递关注状态给事件卡片
- DynamicNewsDetailPanel.js: 移除本地 state，使用 Redux 状态

✅ Mock API 支持
- event.js: 添加 POST /api/events/:eventId/follow 处理器
- 返回 { is_following, follower_count } 模拟数据

✅ Bug 修复
- EventDetail/index.js: 添加 useRef 导入
- concept.js: 导出 generatePopularConcepts 函数
- event.js: 添加 /api/events/:eventId/concepts 处理器

功能：
- 点击滚动列表的关注按钮，详情面板的关注状态自动同步
- 点击详情面板的关注按钮，滚动列表的关注状态自动同步
- 关注人数实时更新
- 状态在整个应用中保持一致

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

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

@@ -31,6 +31,9 @@ import PaginationControl from './PaginationControl';
  * @param {boolean} loading - 加载状态
  * @param {string} mode - 展示模式：'carousel'（单排轮播）| 'grid'（双排网格）
  * @param {Function} onModeChange - 模式切换回调
+ * @param {boolean} hasMore - 是否还有更多数据
+ * @param {Object} eventFollowStatus - 事件关注状态 { [eventId]: { isFollowing, followerCount } }
+ * @param {Function} onToggleFollow - 关注按钮回调
  */
 const EventScrollList = ({
   events,
@@ -42,7 +45,10 @@ const EventScrollList = ({
   onPageChange,
   loading = false,
   mode = 'carousel',
-  onModeChange
+  onModeChange,
+  hasMore = true,
+  eventFollowStatus = {},
+  onToggleFollow
 }) => {
   const scrollContainerRef = useRef(null);
 
@@ -121,7 +127,7 @@ const EventScrollList = ({
       )}
 
       {/* 右侧翻页按钮 - 下一页 */}
-      {currentPage < totalPages && (
+      {currentPage < totalPages && hasMore && (
         <IconButton
           icon={<ChevronRightIcon boxSize={6} color="blue.500" />}
           position="absolute"
@@ -143,6 +149,7 @@ const EventScrollList = ({
             boxShadow: '0 4px 12px rgba(0, 0, 0, 0.2)',
             transform: 'translateY(-50%) scale(1.05)'
           }}
+          isDisabled={currentPage >= totalPages && !hasMore}
           aria-label="下一页"
           title="下一页"
         />
@@ -211,8 +218,8 @@ const EventScrollList = ({
                 <DynamicNewsEventCard
                   event={event}
                   index={index}
-                  isFollowing={false}
-                  followerCount={event.follower_count || 0}
+                  isFollowing={eventFollowStatus[event.id]?.isFollowing || false}
+                  followerCount={eventFollowStatus[event.id]?.followerCount || event.follower_count || 0}
                   isSelected={selectedEvent?.id === event.id}
                   onEventClick={(clickedEvent) => {
                     onEventSelect(clickedEvent);
@@ -222,7 +229,7 @@ const EventScrollList = ({
                     e.stopPropagation();
                     onEventSelect(event);
                   }}
-                  onToggleFollow={() => {}}
+                  onToggleFollow={() => onToggleFollow?.(event.id)}
                   timelineStyle={getTimelineBoxStyle()}
                   borderColor={borderColor}
                 />
@@ -244,8 +251,8 @@ const EventScrollList = ({
                 <DynamicNewsEventCard
                   event={event}
                   index={index}
-                  isFollowing={false}
-                  followerCount={event.follower_count || 0}
+                  isFollowing={eventFollowStatus[event.id]?.isFollowing || false}
+                  followerCount={eventFollowStatus[event.id]?.followerCount || event.follower_count || 0}
                   isSelected={selectedEvent?.id === event.id}
                   onEventClick={(clickedEvent) => {
                     onEventSelect(clickedEvent);
@@ -255,7 +262,7 @@ const EventScrollList = ({
                     e.stopPropagation();
                     onEventSelect(event);
                   }}
-                  onToggleFollow={() => {}}
+                  onToggleFollow={() => onToggleFollow?.(event.id)}
                   timelineStyle={getTimelineBoxStyle()}
                   borderColor={borderColor}
                 />