Implement a complete visual PDF document editor and generation system as a Single Page Application built with SvelteKit. This initial release includes:
Core Engine:
- Document model with hierarchical node types (document, section, row, column, primitives)
- Layout engine with flex-like positioning algorithm
- Tree traversal and manipulation utilities
Visual Editor:
- Canvas-based document preview with page rendering
- Component toolbar with containers, primitives, and complex elements
- Properties panel for editing node styles and content
- Insertion popup for inline element placement
- Strict hierarchy enforcement (document → section → row → column → elements)
PDF Generation:
- Abstract renderer interface for multiple backends
- jsPDF implementation with text, image, and shape rendering
- Document metadata support
State Management:
- Svelte stores for document, selection, and history
- Undo/redo support with command pattern
- JSON import/export for document persistence
Configuration:
- SvelteKit with static adapter
- Tailwind CSS v4 integration
- Vitest for testing
- Prettier for code formatting
- TypeScript with strict mode
