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/MessageMapper.ts

@@ -0,0 +1,194 @@
+/**
+ * 消息数据映射器
+ * 负责 Message 模型与 API 响应、数据库记录之间的转换
+ */
+
+import {
+  MessageModel,
+  MessageSegment,
+  UserModel,
+} from '../models';
+import type {
+  MessageResponse,
+  UserDTO,
+} from '../../types/dto';
+import { safeParseJsonOrUndefined } from '../../database/core/jsonUtils';
+import type { CachedMessage } from '../../database/types/CachedMessage';
+
+// 数据库消息记录类型
+export interface MessageDbRecord {
+  id: string;
+  conversationId: string;
+  senderId: string;
+  content: string | null;
+  type: string;
+  isRead: number;
+  createdAt: string;
+  seq: number;
+  status: string;
+  segments: string | null;
+}
+
+export class MessageMapper {
+  /**
+   * 将 API 响应转换为应用模型
+   */
+  static fromApiResponse(response: MessageResponse): MessageModel {
+    const textSegment = response.segments?.find(s => s.type === 'text');
+    const content = textSegment?.data?.text || textSegment?.data?.content || '';
+
+    return {
+      id: String(response.id || ''),
+      conversationId: String(response.conversation_id || ''),
+      senderId: String(response.sender_id || ''),
+      content,
+      type: 'text',
+      isRead: false,
+      createdAt: new Date(response.created_at || Date.now()),
+      seq: response.seq || 0,
+      status: response.status || 'normal',
+      segments: response.segments || [],
+      replyToId: response.reply_to_id,
+      sender: response.sender ? this.mapSenderFromApi(response.sender) : undefined,
+    };
+  }
+
+  /**
+   * 将 API 响应数组转换为应用模型数组
+   */
+  static fromApiResponseList(responses: MessageResponse[]): MessageModel[] {
+    return responses.map(r => this.fromApiResponse(r));
+  }
+
+  /**
+   * 将数据库记录转换为应用模型
+   */
+  static fromDbRecord(record: MessageDbRecord): MessageModel {
+    return {
+      id: record.id,
+      conversationId: record.conversationId,
+      senderId: record.senderId,
+      content: record.content || undefined,
+      type: record.type || 'text',
+      isRead: record.isRead === 1,
+      createdAt: new Date(record.createdAt),
+      seq: record.seq || 0,
+      status: record.status || 'normal',
+      segments: record.segments ? safeParseJsonOrUndefined<MessageSegment[]>(record.segments) : undefined,
+    };
+  }
+
+  /**
+   * 将数据库记录数组转换为应用模型数组
+   */
+  static fromDbRecordList(records: MessageDbRecord[]): MessageModel[] {
+    return records.map(r => this.fromDbRecord(r));
+  }
+
+  /**
+   * 将应用模型转换为数据库记录
+   */
+  static toDbRecord(model: MessageModel): MessageDbRecord {
+    return {
+      id: model.id,
+      conversationId: model.conversationId,
+      senderId: model.senderId,
+      content: model.content || null,
+      type: model.type,
+      isRead: model.isRead ? 1 : 0,
+      createdAt: model.createdAt.toISOString(),
+      seq: model.seq,
+      status: model.status,
+      segments: model.segments ? JSON.stringify(model.segments) : null,
+    };
+  }
+
+  /**
+   * 将应用模型转换为 API 请求数据
+   */
+  static toApiRequest(model: Partial<MessageModel>): Record<string, any> {
+    const request: Record<string, any> = {};
+
+    if (model.segments) {
+      request.segments = model.segments;
+    }
+    if (model.content) {
+      request.content = model.content;
+    }
+    if (model.type) {
+      request.message_type = model.type;
+    }
+    if (model.replyToId) {
+      request.reply_to_id = model.replyToId;
+    }
+
+    return request;
+  }
+
+  /**
+   * 创建发送消息请求体
+   */
+  static createSendRequest(
+    detailType: 'private' | 'group',
+    segments: MessageSegment[],
+    replyToId?: string
+  ): Record<string, any> {
+    const body: Record<string, any> = {
+      detail_type: detailType,
+      segments,
+    };
+    if (replyToId) {
+      body.reply_to_id = replyToId;
+    }
+    return body;
+  }
+
+  /**
+   * 创建文本消息段
+   */
+  static createTextSegment(text: string): MessageSegment {
+    return {
+      type: 'text',
+      data: { text },
+    };
+  }
+
+  /**
+   * 创建图片消息段
+   */
+  static createImageSegment(url: string): MessageSegment {
+    return {
+      type: 'image',
+      data: { url },
+    };
+  }
+
+
+  private static mapSenderFromApi(sender: UserDTO): UserModel {
+    return {
+      id: String(sender.id || ''),
+      username: sender.username || '',
+      nickname: sender.nickname,
+      avatar: sender.avatar || undefined,
+    };
+  }
+
+  static toCachedMessage(apiMessage: any, conversationId?: string): CachedMessage {
+    return {
+      id: apiMessage.id,
+      conversationId: apiMessage.conversation_id || conversationId || '',
+      senderId: apiMessage.sender_id,
+      content: apiMessage.content,
+      type: apiMessage.type || 'text',
+      isRead: apiMessage.is_read || false,
+      createdAt: apiMessage.created_at,
+      seq: apiMessage.seq,
+      status: apiMessage.status || 'normal',
+      segments: apiMessage.segments,
+    };
+  }
+
+  static toCachedMessages(apiMessages: any[], conversationId?: string): CachedMessage[] {
+    return apiMessages.map(m => this.toCachedMessage(m, conversationId));
+  }
+}