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/uuid_test.go

@@ -0,0 +1,151 @@
+package helpers_test
+
+import (
+	"regexp"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"go.yandata.net/iod/iod/trustlog-sdk/internal/helpers"
+)
+
+func TestNewUUIDv7(t *testing.T) {
+	// UUID v7 格式：无连字符，32个十六进制字符
+	uuidPattern := regexp.MustCompile(`^[0-9a-f]{32}$`)
+
+	t.Run("生成有效的UUID", func(t *testing.T) {
+		uuid := helpers.NewUUIDv7()
+
+		// 验证格式
+		assert.Len(t, uuid, 32, "UUID长度应该是32个字符")
+		assert.Regexp(t, uuidPattern, uuid, "UUID应该只包含小写十六进制字符")
+	})
+
+	t.Run("每次生成的UUID应该不同", func(t *testing.T) {
+		uuid1 := helpers.NewUUIDv7()
+		uuid2 := helpers.NewUUIDv7()
+		uuid3 := helpers.NewUUIDv7()
+
+		assert.NotEqual(t, uuid1, uuid2)
+		assert.NotEqual(t, uuid2, uuid3)
+		assert.NotEqual(t, uuid1, uuid3)
+	})
+
+	t.Run("UUID格式验证", func(t *testing.T) {
+		uuid := helpers.NewUUIDv7()
+
+		// UUID v7 应该是 32 个十六进制字符
+		require.Len(t, uuid, 32)
+
+		// 检查每个字符都是有效的十六进制
+		for i, c := range uuid {
+			assert.True(t,
+				(c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'),
+				"字符 %c 在位置 %d 不是有效的十六进制字符", c, i)
+		}
+	})
+
+	t.Run("并发生成UUID", func(t *testing.T) {
+		const concurrency = 100
+		uuids := make([]string, concurrency)
+		var wg sync.WaitGroup
+		wg.Add(concurrency)
+
+		for i := range concurrency {
+			go func(idx int) {
+				defer wg.Done()
+				uuids[idx] = helpers.NewUUIDv7()
+			}(i)
+		}
+
+		wg.Wait()
+
+		// 验证所有 UUID 都不为空且格式正确
+		for i, uuid := range uuids {
+			assert.NotEmpty(t, uuid, "UUID %d 不应该为空", i)
+			assert.Regexp(t, uuidPattern, uuid, "UUID %d 格式不正确", i)
+		}
+
+		// 验证所有 UUID 都是唯一的
+		uniqueMap := make(map[string]bool)
+		for _, uuid := range uuids {
+			assert.False(t, uniqueMap[uuid], "UUID重复: %s", uuid)
+			uniqueMap[uuid] = true
+		}
+		assert.Len(t, uniqueMap, concurrency, "应该生成%d个唯一的UUID", concurrency)
+	})
+
+	t.Run("UUID包含时间戳信息", func(t *testing.T) {
+		// 连续生成多个UUID，它们的时间戳部分应该相近或递增
+		uuid1 := helpers.NewUUIDv7()
+		uuid2 := helpers.NewUUIDv7()
+
+		// UUID v7 的前12个字符主要是时间戳
+		// 在很短的时间内生成的UUID，时间戳部分应该相同或非常接近
+		timePrefix1 := uuid1[:12]
+		timePrefix2 := uuid2[:12]
+
+		// 时间戳应该相同或第二个略大（因为时间在递增）
+		assert.True(t,
+			timePrefix1 == timePrefix2 || timePrefix1 <= timePrefix2,
+			"UUID的时间戳部分应该单调递增")
+	})
+
+	t.Run("批量生成UUID性能测试", func(t *testing.T) {
+		const iterations = 1000
+		uuids := make([]string, iterations)
+
+		for i := range iterations {
+			uuids[i] = helpers.NewUUIDv7()
+		}
+
+		// 验证所有UUID都有效
+		for i, uuid := range uuids {
+			assert.Regexp(t, uuidPattern, uuid, "UUID %d 格式不正确", i)
+		}
+
+		// 简单的唯一性检查
+		uniqueMap := make(map[string]bool)
+		for _, uuid := range uuids {
+			uniqueMap[uuid] = true
+		}
+		assert.Len(t, uniqueMap, iterations, "应该生成%d个唯一的UUID", iterations)
+	})
+}
+
+func TestNewUUIDv7_Format(t *testing.T) {
+	// 测试UUID v7的具体格式要求
+	uuid := helpers.NewUUIDv7()
+
+	// 总长度 32
+	assert.Len(t, uuid, 32)
+
+	// 全部小写
+	for _, c := range uuid {
+		if c >= 'a' && c <= 'f' {
+			assert.True(t, c >= 'a' && c <= 'f')
+		} else {
+			assert.True(t, c >= '0' && c <= '9')
+		}
+	}
+}
+
+func TestNewUUIDv7_EdgeCases(t *testing.T) {
+	t.Run("快速连续生成", func(t *testing.T) {
+		// 在极短时间内生成多个UUID
+		uuids := make([]string, 10)
+		for i := range 10 {
+			uuids[i] = helpers.NewUUIDv7()
+		}
+
+		// 所有UUID应该都有效且唯一
+		seen := make(map[string]bool)
+		for _, uuid := range uuids {
+			assert.Len(t, uuid, 32)
+			assert.False(t, seen[uuid], "UUID不应该重复")
+			seen[uuid] = true
+		}
+	})
+}