refactor: 重构trustlog-sdk目录结构到trustlog/go-trustlog

- 将所有trustlog-sdk文件移动到trustlog/go-trustlog/目录
- 更新README中所有import路径从trustlog-sdk改为go-trustlog
- 更新cookiecutter配置文件中的项目名称
- 更新根目录.lefthook.yml以引用新位置的配置
- 添加go.sum文件到版本控制
- 删除过时的示例文件

这次重构与trustlog-server保持一致的目录结构，
为未来支持多语言SDK（Python、Java等）预留空间。

internal/helpers/cbor_time_test.go

@@ -0,0 +1,76 @@
+package helpers_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"go.yandata.net/iod/iod/trustlog-sdk/internal/helpers"
+)
+
+func TestCBORTimePrecision(t *testing.T) {
+	t.Parallel()
+
+	// 创建一个包含纳秒精度的时间戳
+	originalTime := time.Date(2024, 1, 1, 12, 30, 45, 123456789, time.UTC)
+
+	t.Logf("Original time: %v", originalTime)
+	t.Logf("Original nanoseconds: %d", originalTime.Nanosecond())
+
+	// 序列化
+	data, err := helpers.MarshalCanonical(originalTime)
+	require.NoError(t, err)
+	require.NotNil(t, data)
+
+	// 反序列化
+	var decodedTime time.Time
+	err = helpers.Unmarshal(data, &decodedTime)
+	require.NoError(t, err)
+
+	t.Logf("Decoded time: %v", decodedTime)
+	t.Logf("Decoded nanoseconds: %d", decodedTime.Nanosecond())
+
+	// 验证纳秒精度是否保留
+	assert.Equal(t, originalTime.UnixNano(), decodedTime.UnixNano(),
+		"纳秒精度应该被保留")
+	assert.Equal(t, originalTime.Nanosecond(), decodedTime.Nanosecond(),
+		"纳秒部分应该相等")
+}
+
+func TestCBORTimePrecision_Struct(t *testing.T) {
+	t.Parallel()
+
+	type TestStruct struct {
+		Timestamp time.Time `cbor:"timestamp"`
+	}
+
+	// 创建一个包含纳秒精度的时间戳
+	originalTime := time.Date(2024, 1, 1, 12, 30, 45, 123456789, time.UTC)
+	original := TestStruct{
+		Timestamp: originalTime,
+	}
+
+	t.Logf("Original timestamp: %v", original.Timestamp)
+	t.Logf("Original nanoseconds: %d", original.Timestamp.Nanosecond())
+
+	// 序列化
+	data, err := helpers.MarshalCanonical(original)
+	require.NoError(t, err)
+	require.NotNil(t, data)
+
+	// 反序列化
+	var decoded TestStruct
+	err = helpers.Unmarshal(data, &decoded)
+	require.NoError(t, err)
+
+	t.Logf("Decoded timestamp: %v", decoded.Timestamp)
+	t.Logf("Decoded nanoseconds: %d", decoded.Timestamp.Nanosecond())
+
+	// 验证纳秒精度是否保留
+	assert.Equal(t, original.Timestamp.UnixNano(), decoded.Timestamp.UnixNano(),
+		"纳秒精度应该被保留")
+	assert.Equal(t, original.Timestamp.Nanosecond(), decoded.Timestamp.Nanosecond(),
+		"纳秒部分应该相等")
+}