fix: auto-fix code issues (cron)

- 修复重复导入/字段
- 修复异常处理
- 修复PEP8格式问题
- 添加类型注解
- 清理未使用的导入
- 统一字符串格式化为f-string
- 修复行长度超过120字符的问题

auto_code_fixer.py

@@ -396,12 +396,12 @@ class CodeFixer:
         if self.manual_issues:
             for issue in self.manual_issues:
                 report.append(
-                    f"- `{issue.file_path}:{issue.line_no}` [{issue.severity}] {issue.message}"
+                    "- `{issue.file_path}:{issue.line_no}` [{issue.severity}] {issue.message}"
                 )
                 if issue.original_line:
-                    report.append(f"  ```python")
-                    report.append(f"  {issue.original_line.strip()}")
-                    report.append(f"  ```")
+                    report.append("  ```python")
+                    report.append("  {issue.original_line.strip()}")
+                    report.append("  ```")
         else:
             report.append("无")
         report.append("")