feat(login):基本完成用户登录，待测。

response/user_response.go

@@ -0,0 +1,29 @@
+package response
+
+import (
+	"electricity_bill_calc/model"
+	"net/http"
+)
+
+type LoginResponse struct {
+	BaseResponse
+	NeedReset bool           `json:"needReset"`
+	Session   *model.Session `json:"session,omitempty"`
+}
+
+func (r *Result) LoginSuccess(session *model.Session, needReset bool) {
+	res := &LoginResponse{}
+	res.Code = http.StatusOK
+	res.Message = "用户已成功登录。"
+	res.NeedReset = needReset
+	res.Session = session
+	r.Ctx.JSON(http.StatusOK, res)
+}
+
+func (r *Result) LoginNeedReset() {
+	res := &LoginResponse{}
+	res.Code = http.StatusUnauthorized
+	res.Message = "用户凭据已失效。"
+	res.NeedReset = true
+	r.Ctx.JSON(http.StatusOK, res)
+}