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/validate_test.go

@@ -0,0 +1,186 @@
+package helpers_test
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"go.yandata.net/iod/iod/trustlog-sdk/internal/helpers"
+)
+
+func TestGetValidator(t *testing.T) {
+	t.Run("返回有效的validator实例", func(t *testing.T) {
+		v := helpers.GetValidator()
+
+		require.NotNil(t, v, "Validator不应该为nil")
+	})
+
+	t.Run("单例模式：多次调用返回同一个实例", func(t *testing.T) {
+		v1 := helpers.GetValidator()
+		v2 := helpers.GetValidator()
+		v3 := helpers.GetValidator()
+
+		// 使用指针比较，确保是同一个实例
+		assert.Same(t, v1, v2, "第一次和第二次调用应该返回同一个实例")
+		assert.Same(t, v2, v3, "第二次和第三次调用应该返回同一个实例")
+		assert.Same(t, v1, v3, "第一次和第三次调用应该返回同一个实例")
+	})
+
+	t.Run("并发获取validator应该安全", func(t *testing.T) {
+		const concurrency = 100
+		validators := make([]interface{}, concurrency)
+		var wg sync.WaitGroup
+		wg.Add(concurrency)
+
+		for i := range concurrency {
+			go func(idx int) {
+				defer wg.Done()
+				v := helpers.GetValidator()
+				// 存储validator实例
+				validators[idx] = v
+			}(i)
+		}
+
+		wg.Wait()
+
+		// 验证所有goroutine获取的是同一个实例
+		firstValidator := validators[0]
+		for i := 1; i < concurrency; i++ {
+			assert.Same(t, firstValidator, validators[i],
+				"并发调用第%d次获取的validator应该与第一次相同", i)
+		}
+	})
+
+	t.Run("validator可以正常工作", func(t *testing.T) {
+		v := helpers.GetValidator()
+
+		// 测试一个简单的结构体验证
+		type TestStruct struct {
+			Name  string `validate:"required,min=2,max=10"`
+			Email string `validate:"required,email"`
+			Age   int    `validate:"gte=0,lte=120"`
+		}
+
+		// 有效的结构体
+		validData := TestStruct{
+			Name:  "John",
+			Email: "john@example.com",
+			Age:   30,
+		}
+		err := v.Struct(validData)
+		require.NoError(t, err, "有效的数据不应该产生验证错误")
+
+		// 无效的结构体 - 缺少必填字段
+		invalidData1 := TestStruct{
+			Name: "",
+			Age:  30,
+		}
+		err = v.Struct(invalidData1)
+		require.Error(t, err, "缺少必填字段应该产生验证错误")
+
+		// 无效的结构体 - 字段值超出范围
+		invalidData2 := TestStruct{
+			Name:  "John",
+			Email: "john@example.com",
+			Age:   150,
+		}
+		err = v.Struct(invalidData2)
+		require.Error(t, err, "年龄超出范围应该产生验证错误")
+
+		// 无效的结构体 - 邮箱格式错误
+		invalidData3 := TestStruct{
+			Name:  "John",
+			Email: "invalid-email",
+			Age:   30,
+		}
+		err = v.Struct(invalidData3)
+		assert.Error(t, err, "无效的邮箱格式应该产生验证错误")
+	})
+}
+
+func TestGetValidator_InitializationOnce(t *testing.T) {
+	// 这个测试验证 sync.Once 确保初始化只执行一次
+	const calls = 1000
+	var wg sync.WaitGroup
+	wg.Add(calls)
+
+	results := make([]interface{}, calls)
+
+	for i := range calls {
+		go func(idx int) {
+			defer wg.Done()
+			v := helpers.GetValidator()
+			results[idx] = v
+		}(i)
+	}
+
+	wg.Wait()
+
+	// 所有结果应该指向同一个实例
+	first := results[0]
+	for i := 1; i < calls; i++ {
+		assert.Same(t, first, results[i],
+			"所有调用应该返回完全相同的validator实例")
+	}
+}
+
+func TestGetValidator_ValidatorFunctionality(t *testing.T) {
+	v := helpers.GetValidator()
+
+	tests := []struct {
+		name    string
+		data    interface{}
+		wantErr bool
+	}{
+		{
+			name: "结构体字段验证-成功",
+			data: struct {
+				Field string `validate:"required"`
+			}{
+				Field: "value",
+			},
+			wantErr: false,
+		},
+		{
+			name: "结构体字段验证-失败",
+			data: struct {
+				Field string `validate:"required"`
+			}{
+				Field: "",
+			},
+			wantErr: true,
+		},
+		{
+			name: "数字范围验证-成功",
+			data: struct {
+				Count int `validate:"min=1,max=100"`
+			}{
+				Count: 50,
+			},
+			wantErr: false,
+		},
+		{
+			name: "数字范围验证-失败",
+			data: struct {
+				Count int `validate:"min=1,max=100"`
+			}{
+				Count: 200,
+			},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := v.Struct(tt.data)
+
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}