feat: 修复重试后请求结构混乱，修复rerank端点无法使用

common/copy.go

@@ -0,0 +1,21 @@
+package common
+
+import (
+	"fmt"
+	"github.com/antlabs/pcopy"
+)
+
+func DeepCopy[T any](src *T) (*T, error) {
+	if src == nil {
+		return nil, fmt.Errorf("copy source cannot be nil")
+	}
+	var dst T
+	err := pcopy.Copy(&dst, src)
+	if err != nil {
+		return nil, err
+	}
+	if &dst == nil {
+		return nil, fmt.Errorf("copy result cannot be nil")
+	}
+	return &dst, nil
+}