feat: 从 React Context 迁移到 Redux，实现了：

1. ✅ 集中式状态管理 - PostHog 状态与应用状态统一管理
  2. ✅ 自动追踪机制 - Middleware 自动拦截 Redux actions 进行追踪
  3. ✅ Redux DevTools 支持 - 可视化调试所有 PostHog 事件
  4. ✅ 离线事件缓存 - 网络恢复时自动刷新缓存事件
  5. ✅ 性能优化 Hooks - 提供轻量级 Hook 避免不必要的重渲染

src/hooks/usePostHogRedux.js

@@ -0,0 +1,272 @@
+// src/hooks/usePostHogRedux.js
+import { useCallback } from 'react';
+import { useDispatch, useSelector } from 'react-redux';
+import {
+  trackEvent,
+  identifyUser,
+  resetUser,
+  optIn,
+  optOut,
+  selectPostHog,
+  selectIsInitialized,
+  selectUser,
+  selectFeatureFlags,
+  selectFeatureFlag,
+  selectIsOptedOut,
+  selectStats,
+  flushCachedEvents,
+} from '../store/slices/posthogSlice';
+import { trackPageView } from '../lib/posthog';
+
+/**
+ * PostHog Redux Hook
+ * 提供便捷的 PostHog 功能访问接口
+ *
+ * 用法示例:
+ *
+ * ```jsx
+ * import { usePostHogRedux } from 'hooks/usePostHogRedux';
+ * import { RETENTION_EVENTS } from 'lib/constants';
+ *
+ * function MyComponent() {
+ *   const { track, identify, user, isInitialized } = usePostHogRedux();
+ *
+ *   const handleClick = () => {
+ *     track(RETENTION_EVENTS.NEWS_ARTICLE_CLICKED, {
+ *       article_id: '123',
+ *       article_title: '标题',
+ *     });
+ *   };
+ *
+ *   if (!isInitialized) {
+ *     return <div>正在加载...</div>;
+ *   }
+ *
+ *   return (
+ *     <div>
+ *       <button onClick={handleClick}>点击追踪</button>
+ *       {user && <p>当前用户: {user.userId}</p>}
+ *     </div>
+ *   );
+ * }
+ * ```
+ */
+export const usePostHogRedux = () => {
+  const dispatch = useDispatch();
+
+  // Selectors
+  const posthog = useSelector(selectPostHog);
+  const isInitialized = useSelector(selectIsInitialized);
+  const user = useSelector(selectUser);
+  const featureFlags = useSelector(selectFeatureFlags);
+  const stats = useSelector(selectStats);
+
+  // ==================== 追踪事件 ====================
+
+  /**
+   * 追踪自定义事件
+   * @param {string} eventName - 事件名称（建议使用 constants.js 中的常量）
+   * @param {object} properties - 事件属性
+   */
+  const track = useCallback(
+    (eventName, properties = {}) => {
+      dispatch(trackEvent({ eventName, properties }));
+    },
+    [dispatch]
+  );
+
+  /**
+   * 追踪页面浏览
+   * @param {string} pagePath - 页面路径
+   * @param {object} properties - 页面属性
+   */
+  const trackPage = useCallback(
+    (pagePath, properties = {}) => {
+      trackPageView(pagePath, properties);
+    },
+    []
+  );
+
+  // ==================== 用户管理 ====================
+
+  /**
+   * 识别用户（登录后调用）
+   * @param {string} userId - 用户 ID
+   * @param {object} userProperties - 用户属性
+   */
+  const identify = useCallback(
+    (userId, userProperties = {}) => {
+      dispatch(identifyUser({ userId, userProperties }));
+    },
+    [dispatch]
+  );
+
+  /**
+   * 重置用户会话（登出时调用）
+   */
+  const reset = useCallback(() => {
+    dispatch(resetUser());
+  }, [dispatch]);
+
+  // ==================== 隐私控制 ====================
+
+  /**
+   * 用户选择退出追踪
+   */
+  const optOutTracking = useCallback(() => {
+    dispatch(optOut());
+  }, [dispatch]);
+
+  /**
+   * 用户选择加入追踪
+   */
+  const optInTracking = useCallback(() => {
+    dispatch(optIn());
+  }, [dispatch]);
+
+  /**
+   * 检查用户是否已退出追踪
+   */
+  const isOptedOut = selectIsOptedOut();
+
+  // ==================== Feature Flags ====================
+
+  /**
+   * 获取特定 Feature Flag 的值
+   * @param {string} flagKey - Flag 键名
+   * @returns {any} Flag 值
+   */
+  const getFlag = useCallback(
+    (flagKey) => {
+      return selectFeatureFlag(flagKey)({ posthog });
+    },
+    [posthog]
+  );
+
+  /**
+   * 检查 Feature Flag 是否启用
+   * @param {string} flagKey - Flag 键名
+   * @returns {boolean}
+   */
+  const isEnabled = useCallback(
+    (flagKey) => {
+      const value = getFlag(flagKey);
+      return Boolean(value);
+    },
+    [getFlag]
+  );
+
+  // ==================== 离线事件管理 ====================
+
+  /**
+   * 刷新缓存的离线事件
+   */
+  const flushEvents = useCallback(() => {
+    dispatch(flushCachedEvents());
+  }, [dispatch]);
+
+  // ==================== 返回接口 ====================
+
+  return {
+    // 状态
+    isInitialized,
+    user,
+    featureFlags,
+    stats,
+    posthog, // 完整的 PostHog 状态
+
+    // 追踪方法
+    track,
+    trackPage,
+
+    // 用户管理
+    identify,
+    reset,
+
+    // 隐私控制
+    optOut: optOutTracking,
+    optIn: optInTracking,
+    isOptedOut,
+
+    // Feature Flags
+    getFlag,
+    isEnabled,
+
+    // 离线事件
+    flushEvents,
+  };
+};
+
+// ==================== 便捷 Hooks ====================
+
+/**
+ * 仅获取追踪功能的 Hook（性能优化）
+ */
+export const usePostHogTrack = () => {
+  const dispatch = useDispatch();
+
+  const track = useCallback(
+    (eventName, properties = {}) => {
+      dispatch(trackEvent({ eventName, properties }));
+    },
+    [dispatch]
+  );
+
+  return { track };
+};
+
+/**
+ * 仅获取 Feature Flags 的 Hook（性能优化）
+ */
+export const usePostHogFlags = () => {
+  const featureFlags = useSelector(selectFeatureFlags);
+  const posthog = useSelector(selectPostHog);
+
+  const getFlag = useCallback(
+    (flagKey) => {
+      return selectFeatureFlag(flagKey)({ posthog });
+    },
+    [posthog]
+  );
+
+  const isEnabled = useCallback(
+    (flagKey) => {
+      const value = getFlag(flagKey);
+      return Boolean(value);
+    },
+    [getFlag]
+  );
+
+  return {
+    featureFlags,
+    getFlag,
+    isEnabled,
+  };
+};
+
+/**
+ * 获取用户信息的 Hook（性能优化）
+ */
+export const usePostHogUser = () => {
+  const user = useSelector(selectUser);
+  const dispatch = useDispatch();
+
+  const identify = useCallback(
+    (userId, userProperties = {}) => {
+      dispatch(identifyUser({ userId, userProperties }));
+    },
+    [dispatch]
+  );
+
+  const reset = useCallback(() => {
+    dispatch(resetUser());
+  }, [dispatch]);
+
+  return {
+    user,
+    identify,
+    reset,
+  };
+};
+
+export default usePostHogRedux;