- Implemented unit tests for the ErrorHandler class, covering error handling, frequency tracking, and performance warnings.
- Created integration tests for input validation, error handling, auto-save functionality, and search/filter systems.
- Developed unit tests for the DataFilter, QuickFilters, and SearchHistory classes to ensure filtering logic works as expected.
- Added tests for the SearchFilterWidget UI component, verifying initialization, filter functionality, and responsiveness.
- Included edge case tests for error handling without UI manager and handling of None values.
- Introduced `quick_test.py` for running specific test categories (unit, integration, theme, all).
- Updated `run_tests.py` to improve test execution and reporting, including coverage.
- Removed outdated test scripts for keyboard shortcuts, menu theming, note saving, and entry updating.
- Added new test script `test_theme_changing.py` to verify theme changing functionality.
- Consolidated integration tests into `test_integration.py` for comprehensive testing of TheChart application.
- Updated theme manager to ensure color retrieval works correctly.
- Modified test constants to import from the correct module path.
