- Introduced validation utilities in src/thechart/validation with InputValidator class for various data types.
- Migrated theme management to thechart.ui.theme_manager, providing a legacy shim for backward compatibility.
- Updated tooltip system to thechart.ui.tooltip_system, maintaining legacy imports.
- Created compatibility shim for undo utilities, redirecting to thechart.core.undo_manager.
- Ensured all new modules are properly documented and maintain existing functionality.
- Added preferences management in `preferences.py` with functions to load, save, get, set, and reset preferences.
- Introduced a configuration directory structure based on the operating system.
- Integrated preferences into the settings window, allowing users to reset settings and manage window geometry.
- Enhanced `search_filter.py` to support flexible date column names and improved filtering logic.
- Updated `settings_window.py` to include options for managing backup and configuration folder paths.
- Introduced an `UndoManager` class to handle undo actions for add/update/delete operations.
- Improved UIManager to support sorting in tree views and added a toast notification feature.
- Created `CONSOLIDATED_DOCS.md` to serve as the primary documentation source, integrating user and developer guides, API references, and troubleshooting sections.
- Updated `README.md` to reference the new consolidated documentation.
- Preserved existing documentation files for backward compatibility, including `USER_GUIDE.md`, `DEVELOPER_GUIDE.md`, and others.
- Enhanced navigation structure in `docs/README.md` to facilitate easier access to documentation.
- Implemented UI flickering fixes, including auto-save optimizations, debounced filter updates, and efficient tree updates to improve user experience.
- Added verification script `verify_docs_consolidation.py` to ensure successful documentation consolidation and integrity.
- 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.
