refactor(message): replace MessageStateManager with zustand store

- Remove MessageStateManager wrapper layer in favor of direct zustand store
- Move service modules to services/ subdirectory (ConversationOperations, MessageDeduplication, MessageSendService, MessageSyncService, ReadReceiptManager, UserCacheService, WSMessageHandler)
- Add new zustand-based store with subscriptionManager for event handling
- Introduce React hooks for message state (useConversations, useMessages, useUnreadCount, etc.)
- Update exports in index.ts to reflect new module structure
- Deprecate messageManager.ts entry point in favor of message/index.ts
- Maintain backward compatibility with existing MessageManager API

src/stores/message/services/UserCacheService.ts

@@ -0,0 +1,119 @@
+/**
+ * 用户信息缓存服务
+ * 管理用户信息的缓存和获取
+ */
+
+import type { MessageResponse, UserDTO } from '../../../types/dto';
+import { api } from '../../../services/api';
+import { getUserCache, saveUserCache } from '../../../services/database';
+import type { IUserCacheService } from '../types';
+
+export class UserCacheService implements IUserCacheService {
+  // 正在获取用户信息的请求映射（用于去重）
+  private pendingUserRequests: Map<string, Promise<UserDTO | null>> = new Map();
+
+  /**
+   * 获取用户信息（带缓存和去重）
+   */
+  async getSenderInfo(userId: string): Promise<UserDTO | null> {
+    // 1. 先检查本地缓存
+    const cachedUser = await getUserCache(userId);
+    if (cachedUser) {
+      return cachedUser;
+    }
+
+    // 2. 检查是否已有正在进行的请求
+    const pendingRequest = this.pendingUserRequests.get(userId);
+    if (pendingRequest) {
+      return pendingRequest;
+    }
+
+    // 3. 发起新请求
+    const request = this.fetchUserInfo(userId);
+    this.pendingUserRequests.set(userId, request);
+
+    try {
+      const user = await request;
+      return user;
+    } finally {
+      // 请求完成后清理
+      this.pendingUserRequests.delete(userId);
+    }
+  }
+
+  /**
+   * 从服务器获取用户信息
+   */
+  private async fetchUserInfo(userId: string): Promise<UserDTO | null> {
+    try {
+      const response = await api.get<UserDTO>(`/users/${userId}`);
+      if (response.code === 0 && response.data) {
+        // 缓存到本地数据库
+        await saveUserCache(response.data);
+        return response.data;
+      }
+      return null;
+    } catch (error) {
+      console.error(`[UserCacheService] 获取用户信息失败: ${userId}`, error);
+      return null;
+    }
+  }
+
+  /**
+   * 批量异步填充消息的 sender 信息
+   * 填充完成后调用 notifyUpdate 更新内存并通知订阅者
+   */
+  enrichMessagesWithSenderInfo(
+    conversationId: string,
+    messages: MessageResponse[],
+    notifyUpdate: (conversationId: string, messages: MessageResponse[]) => void
+  ): void {
+    // 收集所有需要查询的唯一 sender_id（排除系统用户）
+    const senderIds = [...new Set(
+      messages
+        .filter(m => m.sender_id && m.sender_id !== '10000' && !m.sender)
+        .map(m => m.sender_id)
+    )];
+
+    if (senderIds.length === 0) return;
+
+    // 并发获取所有 sender 信息
+    Promise.all(senderIds.map(id => this.getSenderInfo(id).then(user => ({ id, user }))))
+      .then(results => {
+        const senderMap = new Map<string, UserDTO>();
+        results.forEach(({ id, user }) => {
+          if (user) senderMap.set(id, user);
+        });
+
+        if (senderMap.size === 0) return;
+
+        let changed = false;
+        const updated = messages.map(m => {
+          if (!m.sender && m.sender_id && senderMap.has(m.sender_id)) {
+            changed = true;
+            return { ...m, sender: senderMap.get(m.sender_id) };
+          }
+          return m;
+        });
+
+        if (!changed) return;
+
+        // 调用回调通知更新
+        notifyUpdate(conversationId, updated);
+      })
+      .catch(error => {
+        console.error('[UserCacheService] 批量获取 sender 信息失败:', error);
+      });
+  }
+
+  /**
+   * 清除所有待处理的请求
+   * 用于测试或需要重置的场景
+   */
+  reset(): void {
+    this.pendingUserRequests.clear();
+  }
+}
+
+// 单例导出
+export const userCacheService = new UserCacheService();