feat: sale add create user

pkg/utils/time.go

@@ -217,3 +217,23 @@ func ParseCustomTime(s string) (CustomTime, error) {
 	}
 	return ct, nil
 }
+
+// ParseDateOnly 解析 YYYY-MM-DD；空串返回零值（写入 DB 为 NULL）
+func ParseDateOnly(s string) (CustomTime, error) {
+	if s == "" {
+		return CustomTime{}, nil
+	}
+	t, err := time.ParseInLocation(time.DateOnly, s, AsiaShanghai)
+	if err != nil {
+		return CustomTime{}, fmt.Errorf("invalid date format: %s", s)
+	}
+	return CustomTime{Time: t}, nil
+}
+
+// DateString 返回 YYYY-MM-DD；零值返回空串
+func (ct CustomTime) DateString() string {
+	if ct.IsZero() {
+		return ""
+	}
+	return ct.Time.Format(time.DateOnly)
+}