feat: 完善数据库持久化与存证功能

主要更新：

1. 数据库持久化功能
   - 支持三种策略：仅落库、既落库又存证、仅存证
   - 实现 Cursor Worker 异步扫描和存证机制
   - 实现 Retry Worker 失败重试机制
   - 支持 PostgreSQL、MySQL、SQLite 等多种数据库
   - 添加 ClientIP 和 ServerIP 字段（可空，仅落库）

2. 集群并发安全
   - 使用 SELECT FOR UPDATE SKIP LOCKED 防止重复处理
   - 实现 CAS (Compare-And-Set) 原子状态更新
   - 添加 updated_at 字段支持并发控制

3. Cursor 初始化优化
   - 自动基于历史数据初始化 cursor
   - 确保不遗漏任何历史记录
   - 修复 UPSERT 逻辑

4. 测试完善
   - 添加 E2E 集成测试（含 Pulsar 消费者验证）
   - 添加 PostgreSQL 集成测试
   - 添加 Pulsar 集成测试
   - 添加集群并发安全测试
   - 添加 Cursor 初始化验证测试
   - 补充大量单元测试，提升覆盖率

5. 工具脚本
   - 添加数据库迁移脚本
   - 添加 Cursor 状态检查工具
   - 添加 Cursor 初始化工具
   - 添加 Pulsar 消息验证工具

6. 文档清理
   - 删除冗余文档，只保留根目录 README

测试结果：
- 所有 E2E 测试通过（100%）
- 数据库持久化与异步存证流程验证通过
- 集群环境下的并发安全性验证通过
- Cursor 自动初始化和历史数据处理验证通过

api/model/config_signer.go

@@ -7,7 +7,7 @@ import (
 	_ "github.com/crpt/go-crpt/ed25519" // 注册 Ed25519
 	_ "github.com/crpt/go-crpt/sm2"     // 注册 SM2
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/logger"
+	"go.yandata.net/iod/iod/go-trustlog/api/logger"
 )
 
 // ConfigSigner 基于配置的通用签名器

api/model/config_signer_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestNewConfigSigner_SM2(t *testing.T) {

api/model/converter.go

@@ -6,7 +6,7 @@ import (
 
 	"google.golang.org/protobuf/types/known/timestamppb"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/grpc/pb"
+	"go.yandata.net/iod/iod/go-trustlog/api/grpc/pb"
 )
 
 // FromProtobuf 将protobuf的OperationData转换为model.Operation.

api/model/converter_test.go

@@ -8,8 +8,8 @@ import (
 	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/types/known/timestamppb"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/grpc/pb"
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/grpc/pb"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestFromProtobuf_Nil(t *testing.T) {

api/model/crypto_config.go

@@ -11,7 +11,7 @@ import (
 	_ "github.com/crpt/go-crpt/ed25519" // Import Ed25519
 	_ "github.com/crpt/go-crpt/sm2"     // Import SM2
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/logger"
+	"go.yandata.net/iod/iod/go-trustlog/api/logger"
 )
 
 // SignatureAlgorithm 定义支持的签名算法类型.

api/model/crypto_config_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestCryptoConfig_Validate(t *testing.T) {

api/model/envelope_debug_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 // TestSignVerifyDataConsistency 详细测试加签和验签的数据一致性.

api/model/envelope_sign_verify_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 // TestSignVerifyConsistency 测试加签和验签的一致性

api/model/envelope_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestNewEnvelopeConfig(t *testing.T) {

api/model/hash_test.go

@@ -10,7 +10,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestGetHashTool(t *testing.T) {

api/model/operation_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestOperation_Key(t *testing.T) {

api/model/operation_timestamp_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 // TestOperation_TimestampNanosecondPrecision 验证 Operation 的时间戳在 CBOR 序列化/反序列化后能保留纳秒精度

api/model/proof.go

@@ -1,7 +1,7 @@
 package model
 
 import (
-	"go.yandata.net/iod/iod/trustlog-sdk/api/grpc/pb"
+	"go.yandata.net/iod/iod/go-trustlog/api/grpc/pb"
 )
 
 // MerkleTreeProofItem 表示Merkle树证明项.

api/model/proof_test.go

@@ -6,8 +6,8 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/grpc/pb"
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/grpc/pb"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestProofFromProtobuf_Nil(t *testing.T) {

api/model/record_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestRecord_Key(t *testing.T) {

api/model/record_timestamp_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 // TestRecord_TimestampNanosecondPrecision 验证 Record 的时间戳在 CBOR 序列化/反序列化后能保留纳秒精度

api/model/signature.go

@@ -8,7 +8,7 @@ import (
 	"github.com/crpt/go-crpt"
 	_ "github.com/crpt/go-crpt/sm2" // Import SM2 to register it
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/logger"
+	"go.yandata.net/iod/iod/go-trustlog/api/logger"
 )
 
 var (

api/model/signature_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestComputeSignature_EmptyPrivateKey(t *testing.T) {

api/model/signer.go

@@ -3,7 +3,7 @@ package model
 import (
 	"bytes"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/logger"
+	"go.yandata.net/iod/iod/go-trustlog/api/logger"
 )
 
 // Signer 签名器接口，用于抽象不同的签名算法实现。
@@ -127,10 +127,16 @@ func NewNopSigner() *NopSigner {
 	return &NopSigner{}
 }
 
-// Sign 直接返回原数据，不做任何签名操作。
-func (n *NopSigner) Sign(_ []byte) ([]byte, error) {
-
-	return ([]byte)("test"), nil
+// Sign 直接返回原数据的副本，不做任何签名操作。
+func (n *NopSigner) Sign(data []byte) ([]byte, error) {
+	log := logger.GetGlobalLogger()
+	log.Debug("NopSigner: signing data (returning copy)",
+		"dataLength", len(data),
+	)
+	// 返回数据副本
+	result := make([]byte, len(data))
+	copy(result, data)
+	return result, nil
 }
 
 // Verify 验证签名是否等于原数据。

api/model/signer_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestNewSM2Signer(t *testing.T) {

api/model/sm2_consistency_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 // TestSM2HashConsistency 验证SM2加签和验签的一致性

api/model/sm2_hash_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 // TestSM2RequiresHash 测试SM2是否要求预先hash数据

api/model/validation_test.go

@@ -5,7 +5,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"go.yandata.net/iod/iod/trustlog-sdk/api/model"
+	"go.yandata.net/iod/iod/go-trustlog/api/model"
 )
 
 func TestValidationResult_IsProcessing(t *testing.T) {