Major improvements to UI state management and user preferences:
- Add theme toggle with dark/light mode support
- Implement Zustand persist middleware for UI state
- Add ui-store for panel layout preferences (dock width, heights, tabs)
- Persist tool settings (active tool, size, opacity, hardness, etc.)
- Persist canvas view preferences (grid, rulers, snap-to-grid)
- Persist shape tool settings
- Persist collapsible section states
- Fix canvas coordinate transformation for centered rendering
- Constrain checkerboard and grid to canvas bounds
- Add icons to all tab buttons and collapsible sections
- Restructure panel-dock to use persisted state
Storage impact: ~3.5KB total across all preferences
Storage keys: tool-storage, canvas-view-storage, shape-storage, ui-storage
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
Sebastian Krüger
cd59f0606b