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。

.pre-commit-config.yaml

@@ -0,0 +1,39 @@
+default_stages: [commit, push]
+fail_fast: true # stop running hooks at the first failure
+minimum_pre_commit_version: 4.2.0
+
+exclude: |
+  (?x)(
+      cookiecutter-config-file.yml|
+      .cruft.json
+  )
+
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      # Verify syntax
+      - id: check-yaml
+      - id: check-json
+      - id: check-xml
+
+      # Checkers
+      - id: check-merge-conflict # check for merge conflict string
+      - id: detect-private-key # check for existence of private keys
+
+      # Implicit minor corrections to files
+      - id: end-of-file-fixer # ensure all files end with a new line
+      - id: trailing-whitespace # trim trailing whitespaces
+
+      # Good practices for executables/scripts
+      - id: check-executables-have-shebangs # non-binary executables have shebang
+      - id: check-shebang-scripts-are-executable # verify shebang scripts are executable
+
+      # Pretty format JSON files implicitly
+      - id: pretty-format-json
+        args: ["--autofix"]
+
+      # Debatable -- for most projects adding files larger than 10 MB is likely to be
+      # a mistake instead of a requirement. Remove this if needed
+      - id: check-added-large-files # fails if a file larger than 10 MB exists
+        args: ["--maxkb=10240", "--enforce-all"]