Implement unit-testing

Proper unit testing should be done, automated with GitHub actions to ensure the reliability and repeatability of the application.

- [ ] Research application test-suites
- [ ] Develop HDD testing interface
- [ ] Create suite of tests

The issue mentions researching application test-suites and developing an HDD testing interface, but does not specify which files or modules to test. Start by examining the repository structure to understand the codebase, then look for existing tests or testing patterns. Determine what 'HDD testing interface' means in context—check for modules related to HDD monitoring or SMART tools. Creating a suite of tests will require understanding the project's functionality and possibly setting up GitHub Actions workflows.

Written by the indexing model from the issue text.