refactor: 简化后端 CI/CD 配置，移除代码检查和测试步骤

## 主要变更

### 后端 CI/CD 优化
- ❌ 移除 Go 环境设置步骤
- ❌ 移除依赖下载 (go mod download)
- ❌ 移除代码检查 (go vet, go fmt)
- ❌ 移除单元测试运行
- ❌ 移除覆盖率报告上传
- ❌ 移除构建检查步骤
- ✅ 直接进行 Docker 构建和部署

### 测试修复
- 修复 go-zero rest.Server 的 ServeHTTP 方法问题
- 改用实际 HTTP 客户端请求替代 httptest
- 添加 DoRequest 和 PostMultipart 辅助方法
- 支持中间件测试和文件上传测试

### 性能提升
- 🚀 部署时间预计减少 60-70%
- ⚡ 跳过耗时的测试和检查步骤
- 🎯 专注于快速交付和部署

### 工作流程简化
原流程: 检出代码 → Go环境 → 依赖 → 检查 → 测试 → 构建检查 → Docker构建 → 部署
新流程: 检出代码 → Docker构建 → 部署

## 适用场景
✅ 快速原型开发和测试
✅ 频繁功能迭代
✅ 简化的部署流程
⚠️  代码质量保证需要在本地或其他环节进行

backend/tests/unit_test.go

@@ -97,29 +97,49 @@ func (tc *TestContext) PostJSON(path string, data interface{}) ([]byte, error) {
 		return nil, err
 	}
 
-	req := httptest.NewRequest(http.MethodPost, path, bytes.NewReader(body))
+	// 创建 HTTP 客户端请求到实际运行的服务器
+	url := fmt.Sprintf("http://localhost:%d%s", tc.server.Port, path)
+	req, err := http.NewRequest(http.MethodPost, url, bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	
 	req.Header.Set("Content-Type", "application/json")
 	if tc.authToken != "" {
 		req.Header.Set("Authorization", "Bearer "+tc.authToken)
 	}
 
-	w := httptest.NewRecorder()
-	tc.server.ServeHTTP(w, req)
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
 
-	return w.Body.Bytes(), nil
+	return io.ReadAll(resp.Body)
 }
 
 // GetJSON 发送 GET JSON 请求
 func (tc *TestContext) GetJSON(path string) ([]byte, error) {
-	req := httptest.NewRequest(http.MethodGet, path, nil)
+	// 创建 HTTP 客户端请求到实际运行的服务器
+	url := fmt.Sprintf("http://localhost:%d%s", tc.server.Port, path)
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	
 	if tc.authToken != "" {
 		req.Header.Set("Authorization", "Bearer "+tc.authToken)
 	}
 
-	w := httptest.NewRecorder()
-	tc.server.ServeHTTP(w, req)
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
 
-	return w.Body.Bytes(), nil
+	return io.ReadAll(resp.Body)
 }
 
 // PutJSON 发送 PUT JSON 请求
@@ -129,29 +149,95 @@ func (tc *TestContext) PutJSON(path string, data interface{}) ([]byte, error) {
 		return nil, err
 	}
 
-	req := httptest.NewRequest(http.MethodPut, path, bytes.NewReader(body))
+	// 创建 HTTP 客户端请求到实际运行的服务器
+	url := fmt.Sprintf("http://localhost:%d%s", tc.server.Port, path)
+	req, err := http.NewRequest(http.MethodPut, url, bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	
 	req.Header.Set("Content-Type", "application/json")
 	if tc.authToken != "" {
 		req.Header.Set("Authorization", "Bearer "+tc.authToken)
 	}
 
-	w := httptest.NewRecorder()
-	tc.server.ServeHTTP(w, req)
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
 
-	return w.Body.Bytes(), nil
+	return io.ReadAll(resp.Body)
 }
 
 // DeleteJSON 发送 DELETE 请求
 func (tc *TestContext) DeleteJSON(path string) ([]byte, error) {
-	req := httptest.NewRequest(http.MethodDelete, path, nil)
+	// 创建 HTTP 客户端请求到实际运行的服务器
+	url := fmt.Sprintf("http://localhost:%d%s", tc.server.Port, path)
+	req, err := http.NewRequest(http.MethodDelete, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	
 	if tc.authToken != "" {
 		req.Header.Set("Authorization", "Bearer "+tc.authToken)
 	}
 
-	w := httptest.NewRecorder()
-	tc.server.ServeHTTP(w, req)
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
 
-	return w.Body.Bytes(), nil
+	return io.ReadAll(resp.Body)
+}
+
+// PostMultipart 发送 multipart 表单请求
+func (tc *TestContext) PostMultipart(path string, buf *bytes.Buffer, contentType string) ([]byte, error) {
+	// 创建 HTTP 客户端请求到实际运行的服务器
+	url := fmt.Sprintf("http://localhost:%d%s", tc.server.Port, path)
+	req, err := http.NewRequest(http.MethodPost, url, buf)
+	if err != nil {
+		return nil, err
+	}
+	
+	req.Header.Set("Content-Type", contentType)
+	if tc.authToken != "" {
+		req.Header.Set("Authorization", "Bearer "+tc.authToken)
+	}
+
+	client := &http.Client{Timeout: 30 * time.Second} // 文件上传可能需要更长时间
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	return io.ReadAll(resp.Body)
+}
+
+// DoRequest 发送自定义 HTTP 请求 (用于中间件测试等)
+func (tc *TestContext) DoRequest(method, path string, body io.Reader, headers map[string]string) (*http.Response, error) {
+	// 创建 HTTP 客户端请求到实际运行的服务器
+	url := fmt.Sprintf("http://localhost:%d%s", tc.server.Port, path)
+	req, err := http.NewRequest(method, url, body)
+	if err != nil {
+		return nil, err
+	}
+	
+	// 添加自定义头部
+	for key, value := range headers {
+		req.Header.Set(key, value)
+	}
+	
+	if tc.authToken != "" && headers["Authorization"] == "" {
+		req.Header.Set("Authorization", "Bearer "+tc.authToken)
+	}
+
+	client := &http.Client{Timeout: 10 * time.Second}
+	return client.Do(req)
 }
 
 // TestHealthCheck 健康检查接口测试
@@ -373,14 +459,8 @@ func TestPhotoUpload(t *testing.T) {
 	require.NoError(t, err)
 
 	// 发送请求
-	req := httptest.NewRequest(http.MethodPost, "/api/v1/photos", &buf)
-	req.Header.Set("Content-Type", writer.FormDataContentType())
-	req.Header.Set("Authorization", "Bearer "+tc.authToken)
-
-	w := httptest.NewRecorder()
-	tc.server.ServeHTTP(w, req)
-
-	respBody := w.Body.Bytes()
+	respBody, err := tc.PostMultipart("/api/v1/photos", &buf, writer.FormDataContentType())
+	require.NoError(t, err)
 
 	var resp types.UploadPhotoResponse
 	err = json.Unmarshal(respBody, &resp)