refactor: 架构重构 - 解耦过度耦合模块

主要改动:
1. 创建乐观更新工具函数 (optimisticUpdate.ts)
   - 消除 userStore.ts 中的重复代码

2. 拆分 useResponsive.ts (485行 -> 12个专注模块)
   - useBreakpoint: 断点检测
   - useOrientation: 方向检测
   - usePlatform: 平台检测
   - useScreenSize: 屏幕尺寸
   - useResponsiveValue: 响应式值
   - useResponsiveStyle: 响应式样式
   - useMediaQuery: 媒体查询
   - useColumnCount: 列数计算
   - useResponsiveSpacing: 响应式间距

3. 整理数据层 (Repository 层)
   - ApiDataSource: API数据源
   - LocalDataSource: 本地数据源
   - CacheDataSource: 缓存数据源
   - MessageRepository: 消息仓库

4. 重构 messageManager.ts (2194行 -> 4个模块)
   - MessageStateManager: 状态管理
   - WebSocketMessageHandler: WebSocket处理
   - MessageSyncService: 消息同步
   - ReadReceiptManager: 已读管理

5. 导航解耦 (MainNavigator.tsx: 1118行 -> 100行)
   - 创建 NavigationService 解耦层
   - 拆分多个 Navigator 组件

架构改进:
- 单一职责原则: 每个模块职责明确
- 依赖倒置: 通过接口解耦
- 代码复用: 工具函数可被多处使用
- 可测试性: 各模块可独立测试

src/data/models/index.ts

@@ -0,0 +1,153 @@
+/**
+ * Repository 层模型定义
+ * 定义应用内部使用的数据模型，与 API 响应和数据库结构解耦
+ */
+
+// ==================== 消息模型 ====================
+
+export interface MessageSegment {
+  type: string;
+  data: Record<string, any>;
+}
+
+export interface MessageModel {
+  id: string;
+  conversationId: string;
+  senderId: string;
+  content?: string;
+  type: 'text' | 'image' | 'file' | 'system' | string;
+  isRead: boolean;
+  createdAt: Date;
+  seq: number;
+  status: 'normal' | 'recalled' | 'deleted' | string;
+  segments?: MessageSegment[];
+  replyToId?: string;
+  sender?: UserModel;
+}
+
+// ==================== 会话模型 ====================
+
+export type ConversationType = 'private' | 'group';
+
+export interface ConversationModel {
+  id: string;
+  type: ConversationType;
+  participantId: string;
+  lastMessageId?: string;
+  lastMessage?: MessageModel;
+  lastSeq: number;
+  myLastReadSeq: number;
+  otherLastReadSeq: number;
+  unreadCount: number;
+  isPinned: boolean;
+  participants?: UserModel[];
+  group?: GroupModel;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+// ==================== 用户模型 ====================
+
+export interface UserModel {
+  id: string;
+  username: string;
+  nickname?: string;
+  avatar?: string;
+  bio?: string;
+  website?: string;
+  location?: string;
+  email?: string;
+  phone?: string;
+  followersCount?: number;
+  followingCount?: number;
+  postsCount?: number;
+  isFollowing?: boolean;
+  isBlocked?: boolean;
+  createdAt?: Date;
+  updatedAt?: Date;
+}
+
+// ==================== 帖子模型 ====================
+
+export interface PostModel {
+  id: string;
+  authorId: string;
+  author?: UserModel;
+  title: string;
+  content: string;
+  images?: string[];
+  likeCount: number;
+  commentCount: number;
+  shareCount: number;
+  viewCount: number;
+  favoriteCount: number;
+  isLiked: boolean;
+  isFavorited: boolean;
+  isTop: boolean;
+  status: 'published' | 'draft' | 'deleted';
+  communityId?: string;
+  tags?: string[];
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+// ==================== 群组模型 ====================
+
+export type GroupMemberRole = 'owner' | 'admin' | 'member';
+export type GroupJoinType = 'anyone' | 'approval' | 'invite';
+
+export interface GroupMemberModel {
+  userId: string;
+  user?: UserModel;
+  role: GroupMemberRole;
+  nickname?: string;
+  joinTime: Date;
+  muteUntil?: Date;
+  isMuted?: boolean;
+}
+
+export interface GroupModel {
+  id: string;
+  name: string;
+  avatar?: string;
+  description?: string;
+  announcement?: string;
+  ownerId: string;
+  owner?: UserModel;
+  memberCount: number;
+  maxMemberCount: number;
+  joinType: GroupJoinType;
+  isMuted: boolean;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+// ==================== 分页模型 ====================
+
+export interface PaginatedResult<T> {
+  list: T[];
+  total: number;
+  page: number;
+  pageSize: number;
+  totalPages: number;
+  hasMore: boolean;
+}
+
+// ==================== 通用操作结果 ====================
+
+export interface OperationResult<T = void> {
+  success: boolean;
+  data?: T;
+  error?: string;
+  code?: string;
+}
+
+// ==================== 同步状态模型 ====================
+
+export interface SyncStatus {
+  entityType: string;
+  entityId: string;
+  lastSyncedAt: Date;
+  syncVersion: number;
+  pendingChanges: boolean;
+}