init: hgmj server initial commit

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

common/stderr/customerr.go

@@ -0,0 +1,31 @@
+package stderr
+
+import "fmt"
+
+// CustomErr 代替/common/error中的定义，逐渐在代码中弃掉(common/error模块)
+type CustomErr struct {
+	Code Code   `json:"code"`
+	Msg  string `json:"msg"`
+	Tips string `json:"tips"`
+}
+
+// NewCustomErr an error
+func NewCustomErr(code Code, Msg string, tips ...string) *CustomErr {
+	res := &CustomErr{
+		Code: code,
+		Msg:  Msg,
+		Tips: Msg,
+	}
+	if len(tips) > 0 {
+		res.Tips = tips[0]
+	}
+	return res
+}
+
+// Error 返回字符串
+func (s *CustomErr) Error() string {
+	if s == nil {
+		return ""
+	}
+	return fmt.Sprintf("code = %d, msg = %s ,tips = %v", s.Code, s.Msg, s.Tips)
+}