fix: 修复 *time.Time 字段扫描失败及 time.Time 精度丢失问题

- createColumnScans: *time.Time 等指针到结构体类型改用 *interface{} 扫描目标，
  避免 database/sql 因无法将 []byte 转换为 *time.Time 而报 scan error
- ScanStruct: time.Time 值直接存入 record，跳过 toJSONRawMessage 格式化，
  保留纳秒精度和时区 Location
- SafeSetVarValue: 新增 T→*T 赋值路径（适用于 time.Time→*time.Time 等场景），
  以及从 *json.RawMessage 解析 *time.Time 的路径（处理 []byte datetime 字符串）
- 新增 parseTimeFromRaw 支持 MySQL datetime、date-only、ISO8601、RFC3339 等格式
- 新增测试：覆盖 time.Time/[]byte 驱动值、date-only 格式、NULL 指针等场景

exec/query_executor_internal_test.go

@@ -1426,6 +1426,93 @@ func (qes *queryExecutorSuite) TestScanVal_withStruct_sqlScanner() {
 	qes.Equal(sql.NullString{String: "hello", Valid: true}, ns)
 }
 
+// TestScanStructs_timeField_fromTime 验证 time.Time 和 *time.Time 字段直接从 time.Time 驱动值扫描，
+// 纳秒精度和时区 Location 必须原样保留。
+func (qes *queryExecutorSuite) TestScanStructs_timeField_fromTime() {
+	type Row struct {
+		T  time.Time  `db:"t"`
+		PT *time.Time `db:"pt"`
+	}
+	db, mock, err := sqlmock.New()
+	qes.NoError(err)
+	now := time.Now() // 含纳秒、Local 时区
+	mock.ExpectQuery(`SELECT \* FROM "items"`).
+		WillReturnRows(sqlmock.NewRows([]string{"t", "pt"}).
+			AddRow(now, now).
+			AddRow(now, nil),
+		)
+
+	e := newQueryExecutor(db, nil, `SELECT * FROM "items"`)
+	var items []Row
+	qes.NoError(e.ScanStructs(&items))
+	qes.Len(items, 2)
+
+	// 时间相等（Equal 只比较时刻，不比较 Location）
+	qes.True(items[0].T.Equal(now))
+	qes.NotNil(items[0].PT)
+	qes.True(items[0].PT.Equal(now))
+	// 纳秒精度保留
+	qes.Equal(now.Nanosecond(), items[0].T.Nanosecond())
+	qes.Equal(now.Nanosecond(), items[0].PT.Nanosecond())
+	// NULL → nil 指针
+	qes.Nil(items[1].PT)
+}
+
+// TestScanStructs_timeField_fromBytes 验证 time.Time 和 *time.Time 字段从 []byte 字符串扫描，
+// 模拟 MySQL 驱动不配置 parseTime=true 时返回 []byte 的场景（原 bug：scan error on *time.Time）。
+func (qes *queryExecutorSuite) TestScanStructs_timeField_fromBytes() {
+	type Row struct {
+		CreatedAt time.Time  `db:"created_at"`
+		RetryAt   *time.Time `db:"retry_at"`
+	}
+	db, mock, err := sqlmock.New(sqlmock.ValueConverterOption(anyValueConverter{}))
+	qes.NoError(err)
+
+	datetimeBytes := []byte("2024-03-15 10:30:45")
+	mock.ExpectQuery(`SELECT \* FROM "items"`).
+		WillReturnRows(mock.NewRows([]string{"created_at", "retry_at"}).
+			AddRow(datetimeBytes, datetimeBytes).
+			AddRow(datetimeBytes, nil),
+		)
+
+	e := newQueryExecutor(db, nil, `SELECT * FROM "items"`)
+	var items []Row
+	qes.NoError(e.ScanStructs(&items))
+	qes.Len(items, 2)
+
+	want := time.Date(2024, 3, 15, 10, 30, 45, 0, time.UTC)
+	qes.True(items[0].CreatedAt.Equal(want))
+	qes.NotNil(items[0].RetryAt)
+	qes.True(items[0].RetryAt.Equal(want))
+	qes.Nil(items[1].RetryAt)
+}
+
+// TestScanStructs_timeField_fromDateOnlyBytes 验证仅含日期的 []byte（无时分秒）也能正确解析。
+func (qes *queryExecutorSuite) TestScanStructs_timeField_fromDateOnlyBytes() {
+	type Row struct {
+		Birthday  time.Time  `db:"birthday"`
+		ExpiredAt *time.Time `db:"expired_at"`
+	}
+	db, mock, err := sqlmock.New(sqlmock.ValueConverterOption(anyValueConverter{}))
+	qes.NoError(err)
+
+	dateBytes := []byte("2024-03-15")
+	mock.ExpectQuery(`SELECT \* FROM "items"`).
+		WillReturnRows(mock.NewRows([]string{"birthday", "expired_at"}).
+			AddRow(dateBytes, dateBytes),
+		)
+
+	e := newQueryExecutor(db, nil, `SELECT * FROM "items"`)
+	var items []Row
+	qes.NoError(e.ScanStructs(&items))
+	qes.Len(items, 1)
+
+	want := time.Date(2024, 3, 15, 0, 0, 0, 0, time.UTC)
+	qes.True(items[0].Birthday.Equal(want))
+	qes.NotNil(items[0].ExpiredAt)
+	qes.True(items[0].ExpiredAt.Equal(want))
+}
+
 func TestQueryExecutorSuite(t *testing.T) {
 	suite.Run(t, new(queryExecutorSuite))
 }