- Added a new `PlainSlider` widget for keyboard-editable numeric sliders.
- Updated various panels to utilize the new `PlainSlider` for better user interaction.
- Removed unused code and dead code warnings across multiple files.
- Improved organization of modules by adding a `widgets` module.
- Cleaned up imports in several files to streamline the codebase.
- Added Qodana configuration file for code analysis and quality checks.
- Add `persistence.rs` for stable serialization of dock layouts without runtime identifiers.
- Introduce `preview.rs` for geometry handling of dock drop previews.
- Create `sizing.rs` to manage content-aware sizing policies and constraint solving for dock panels.
- Implement `welcome.rs` to provide a welcome surface when no documents are open, featuring New and Open actions.