* fix(persistence): implement path traversal checks
- Updated test cases to expect no errors for valid paths with double slashes and mixed traversal.
- Enhanced the `checkPathTraversal` method to clean the key using `path.Clean` to prevent path traversal vulnerabilities.
- Removed redundant checks in the `getFilePath`, `Save`, `Load`, and `Delete` methods, simplifying the code while maintaining security.
* refactor(tests): simplify persistence tests using testify assertions
- Replaced manual error handling with testify's assert functions for cleaner test code.
- Improved readability and maintainability of test cases by using assertions for error checks and value comparisons.
- Ensured that all tests continue to validate the expected behavior of the persistence layer.
Byron.wang