refactor: restructure core architecture and responsive system

This commit implements a major architectural refactor to improve modularity, type safety, and maintainability across the codebase.

Key changes include:
- **Responsive System Refactor**: Migrated from a monolithic `useResponsive` hook to a set of specialized, granular hooks (`useBreakpoint`, `useOrientation`, `usePlatform`, etc.) located in `src/presentation/hooks/responsive`. This reduces unnecessary re-renders and improves developer experience.
- **Core Service Restructuring**: Introduced a new directory structure for services, including dedicated folders for `datasources`, `mappers`, and domain-specific types (`message`, `post`).
- **Data Layer Improvements**:
    - Centralized JSON parsing logic in `src/database/core/jsonUtils.ts`.
    - Cleaned up repository implementations by removing redundant local utility functions.
    - Refactored `MessageMapper` to use the new centralized JSON utility.
- **Type System Cleanup**:
    - Decomposed the large `src/types/dto.ts` into a modular `src/types/dto/` directory.
    - Simplified `src/types/index.ts` and introduced backward-compatible aliases for core entities.
- **Utility Consolidation**:
    - Created a centralized `src/utils/formatTime.ts` to replace fragmented date formatting logic across various screens and components.
    - Removed deprecated responsive utility files in favor of the new hook-based system.
- **Service Logic Refinement**: Refactored `ApiClient` and `WebSocketService` to use a centralized `showVerificationModal` service, removing duplicated state management for verification prompts.

src/services/mappers/UserMapper.ts

@@ -0,0 +1,134 @@
+/**
+ * 用户数据映射器
+ * 负责 User 模型与 API 响应、数据库记录之间的转换
+ */
+
+import { UserModel } from '../models';
+import type { UserDTO } from '../../types/dto';
+
+// 数据库用户记录类型
+export interface UserDbRecord {
+  id: string;
+  data: string;
+  updatedAt: string;
+}
+
+export class UserMapper {
+  static fromDTO(dto: UserDTO): UserModel {
+    return {
+      id: String(dto.id || ''),
+      username: dto.username || '',
+      nickname: dto.nickname,
+      avatar: dto.avatar,
+      bio: dto.bio,
+      website: dto.website,
+      location: dto.location,
+      email: dto.email,
+      phone: dto.phone,
+      followersCount: dto.followers_count,
+      followingCount: dto.following_count,
+      postsCount: dto.posts_count,
+      isFollowing: dto.is_following,
+      createdAt: dto.created_at ? new Date(dto.created_at) : undefined,
+    };
+  }
+
+  static fromDTOList(dtos: UserDTO[]): UserModel[] {
+    return dtos.map(dto => this.fromDTO(dto));
+  }
+
+  /**
+   * 从数据库记录转换为应用模型
+   */
+  static fromDbRecord(record: UserDbRecord): UserModel | null {
+    try {
+      const data = JSON.parse(record.data) as UserDTO;
+      return this.fromDTO(data);
+    } catch {
+      return null;
+    }
+  }
+
+  /**
+   * 将应用模型转换为数据库记录
+   */
+  static toDbRecord(model: UserModel): UserDbRecord {
+    const dto: UserDTO = {
+      id: model.id,
+      username: model.username,
+      nickname: model.nickname || '',
+      avatar: model.avatar || '',
+      cover_url: '',
+      bio: model.bio || '',
+      website: model.website || '',
+      location: model.location || '',
+      email: model.email,
+      phone: model.phone,
+      followers_count: model.followersCount || 0,
+      following_count: model.followingCount || 0,
+      posts_count: model.postsCount || 0,
+      is_following: model.isFollowing,
+      created_at: model.createdAt?.toISOString() || '',
+    };
+
+    return {
+      id: model.id,
+      data: JSON.stringify(dto),
+      updatedAt: new Date().toISOString(),
+    };
+  }
+
+  /**
+   * 将应用模型转换为 API 请求数据
+   */
+  static toApiRequest(model: Partial<UserModel>): Record<string, any> {
+    const request: Record<string, any> = {};
+
+    if (model.nickname !== undefined) {
+      request.nickname = model.nickname;
+    }
+    if (model.avatar !== undefined) {
+      request.avatar = model.avatar;
+    }
+    if (model.bio !== undefined) {
+      request.bio = model.bio;
+    }
+    if (model.website !== undefined) {
+      request.website = model.website;
+    }
+    if (model.location !== undefined) {
+      request.location = model.location;
+    }
+    if (model.phone !== undefined) {
+      request.phone = model.phone;
+    }
+    if (model.email !== undefined) {
+      request.email = model.email;
+    }
+
+    return request;
+  }
+
+  /**
+   * 将应用模型转换为 DTO
+   */
+  static toDTO(model: UserModel): UserDTO {
+    return {
+      id: model.id,
+      username: model.username,
+      nickname: model.nickname || '',
+      avatar: model.avatar || '',
+      cover_url: '',
+      bio: model.bio || '',
+      website: model.website || '',
+      location: model.location || '',
+      email: model.email,
+      phone: model.phone,
+      followers_count: model.followersCount || 0,
+      following_count: model.followingCount || 0,
+      posts_count: model.postsCount || 0,
+      is_following: model.isFollowing,
+      created_at: model.createdAt?.toISOString() || '',
+    };
+  }
+}