- Change presets from flat array to 2D grid layout
- Add presets_flat array for backward compatibility
- Support 3-column grid layout for preset positioning
- Add drag-and-drop to reorder presets in tabs (2D grid layout)
- Add drag-and-drop to reorder colors within presets
- Add max_colors field to pattern definitions
- Hide color section when max_colors is 0
- Validate color count against pattern max_colors limit
- Store presets in 2D grid format (3 columns)
- Remove left panel from tab content, show only presets
- Update color palette to show swatches instead of hex codes
- Improve preset editor UI with visual color swatches
