feat(common): 新增基础设施 HAR（网络/鉴权/日志/状态/工具）

common/src/main/ets/network/HttpClient.ets

@@ -0,0 +1,65 @@
+import { http } from '@kit.NetworkKit';
+import { HttpInterceptor } from './HttpInterceptor';
+import { ApiError } from './ApiError';
+
+/**
+ * HTTP 客户端封装：统一超时、请求头、拦截器链。
+ * 基于 @kit.NetworkKit 的 http 模块（Promise 风格）。
+ */
+export class HttpClient {
+  private readonly client: http.HttpRequest = http.createHttp();
+  private interceptors: HttpInterceptor[] = [];
+
+  addInterceptor(interceptor: HttpInterceptor): HttpClient {
+    this.interceptors.push(interceptor);
+    return this;
+  }
+
+  async get(url: string, header?: Record<string, string>): Promise<string> {
+    return this.request(url, http.RequestMethod.GET, undefined, header);
+  }
+
+  async post(url: string, body: string, header?: Record<string, string>): Promise<string> {
+    return this.request(url, http.RequestMethod.POST, body, header);
+  }
+
+  async put(url: string, body: string, header?: Record<string, string>): Promise<string> {
+    return this.request(url, http.RequestMethod.PUT, body, header);
+  }
+
+  async delete(url: string, header?: Record<string, string>): Promise<string> {
+    return this.request(url, http.RequestMethod.DELETE, undefined, header);
+  }
+
+  private async request(url: string, method: http.RequestMethod, body?: string,
+    header?: Record<string, string>): Promise<string> {
+    let headers: Record<string, string> = {};
+    if (header !== undefined) {
+      headers = header;
+    }
+    for (const interceptor of this.interceptors) {
+      headers = interceptor.onRequest(headers);
+    }
+
+    const options: http.HttpRequestOptions = {
+      method: method,
+      header: headers,
+      expectDataType: http.HttpDataType.STRING,
+      connectTimeout: 10000,
+      readTimeout: 10000
+    };
+    if (body !== undefined) {
+      options.extraData = body;
+    }
+
+    try {
+      const response: http.HttpResponse = await this.client.request(url, options);
+      for (const interceptor of this.interceptors) {
+        interceptor.onResponse(response.responseCode, response.result as string);
+      }
+      return response.result as string;
+    } catch (err) {
+      throw ApiError.network(JSON.stringify(err));
+    }
+  }
+}