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。

api/model/proof.go

@@ -0,0 +1,146 @@
+package model
+
+import (
+	"go.yandata.net/iod/iod/trustlog-sdk/api/grpc/pb"
+)
+
+// MerkleTreeProofItem 表示Merkle树证明项.
+type MerkleTreeProofItem struct {
+	Floor uint32 // 层级
+	Hash  string // 哈希值
+	Left  bool   // 是否为左节点
+}
+
+// Proof 表示取证证明.
+type Proof struct {
+	ColItems    []*MerkleTreeProofItem // 集合项证明
+	RawItems    []*MerkleTreeProofItem // 原始项证明
+	ColRootItem []*MerkleTreeProofItem // 集合根项证明
+	RawRootItem []*MerkleTreeProofItem // 原始根项证明
+	Sign        string                 // 签名
+	Version     string                 // 版本号
+}
+
+// ProofFromProtobuf 将protobuf的Proof转换为model.Proof.
+func ProofFromProtobuf(pbProof *pb.Proof) *Proof {
+	if pbProof == nil {
+		return nil
+	}
+
+	proof := &Proof{
+		Sign:    pbProof.GetSign(),
+		Version: pbProof.GetVersion(),
+	}
+
+	// 转换 ColItems
+	if pbColItems := pbProof.GetColItems(); len(pbColItems) > 0 {
+		proof.ColItems = make([]*MerkleTreeProofItem, 0, len(pbColItems))
+		for _, item := range pbColItems {
+			proof.ColItems = append(proof.ColItems, &MerkleTreeProofItem{
+				Floor: item.GetFloor(),
+				Hash:  item.GetHash(),
+				Left:  item.GetLeft(),
+			})
+		}
+	}
+
+	// 转换 RawItems
+	if pbRawItems := pbProof.GetRawItems(); len(pbRawItems) > 0 {
+		proof.RawItems = make([]*MerkleTreeProofItem, 0, len(pbRawItems))
+		for _, item := range pbRawItems {
+			proof.RawItems = append(proof.RawItems, &MerkleTreeProofItem{
+				Floor: item.GetFloor(),
+				Hash:  item.GetHash(),
+				Left:  item.GetLeft(),
+			})
+		}
+	}
+
+	// 转换 ColRootItem
+	if pbColRootItem := pbProof.GetColRootItem(); len(pbColRootItem) > 0 {
+		proof.ColRootItem = make([]*MerkleTreeProofItem, 0, len(pbColRootItem))
+		for _, item := range pbColRootItem {
+			proof.ColRootItem = append(proof.ColRootItem, &MerkleTreeProofItem{
+				Floor: item.GetFloor(),
+				Hash:  item.GetHash(),
+				Left:  item.GetLeft(),
+			})
+		}
+	}
+
+	// 转换 RawRootItem
+	if pbRawRootItem := pbProof.GetRawRootItem(); len(pbRawRootItem) > 0 {
+		proof.RawRootItem = make([]*MerkleTreeProofItem, 0, len(pbRawRootItem))
+		for _, item := range pbRawRootItem {
+			proof.RawRootItem = append(proof.RawRootItem, &MerkleTreeProofItem{
+				Floor: item.GetFloor(),
+				Hash:  item.GetHash(),
+				Left:  item.GetLeft(),
+			})
+		}
+	}
+
+	return proof
+}
+
+// ProofToProtobuf 将model.Proof转换为protobuf的Proof.
+func ProofToProtobuf(proof *Proof) *pb.Proof {
+	if proof == nil {
+		return nil
+	}
+
+	pbProof := &pb.Proof{
+		Sign:    proof.Sign,
+		Version: proof.Version,
+	}
+
+	// 转换 ColItems
+	if len(proof.ColItems) > 0 {
+		pbProof.ColItems = make([]*pb.MerkleTreeProofItem, 0, len(proof.ColItems))
+		for _, item := range proof.ColItems {
+			pbProof.ColItems = append(pbProof.ColItems, &pb.MerkleTreeProofItem{
+				Floor: item.Floor,
+				Hash:  item.Hash,
+				Left:  item.Left,
+			})
+		}
+	}
+
+	// 转换 RawItems
+	if len(proof.RawItems) > 0 {
+		pbProof.RawItems = make([]*pb.MerkleTreeProofItem, 0, len(proof.RawItems))
+		for _, item := range proof.RawItems {
+			pbProof.RawItems = append(pbProof.RawItems, &pb.MerkleTreeProofItem{
+				Floor: item.Floor,
+				Hash:  item.Hash,
+				Left:  item.Left,
+			})
+		}
+	}
+
+	// 转换 ColRootItem
+	if len(proof.ColRootItem) > 0 {
+		pbProof.ColRootItem = make([]*pb.MerkleTreeProofItem, 0, len(proof.ColRootItem))
+		for _, item := range proof.ColRootItem {
+			pbProof.ColRootItem = append(pbProof.ColRootItem, &pb.MerkleTreeProofItem{
+				Floor: item.Floor,
+				Hash:  item.Hash,
+				Left:  item.Left,
+			})
+		}
+	}
+
+	// 转换 RawRootItem
+	if len(proof.RawRootItem) > 0 {
+		pbProof.RawRootItem = make([]*pb.MerkleTreeProofItem, 0, len(proof.RawRootItem))
+		for _, item := range proof.RawRootItem {
+			pbProof.RawRootItem = append(pbProof.RawRootItem, &pb.MerkleTreeProofItem{
+				Floor: item.Floor,
+				Hash:  item.Hash,
+				Left:  item.Left,
+			})
+		}
+	}
+
+	return pbProof
+}