v0.2.0

## What's new in v0.2.0

### Roof system rewrite
- Complete rewrite of roof geometry generation with proper hip, gable, and mansard support
- New `roof-segment` node type for individual roof face control
- Dedicated roof materials system with per-segment material overrides

### Scene store refactor
- Rearchitected scene store for better performance and cleaner state management
- Improved node action handlers with roof-segment awareness

### Spatial grid improvements
- Spatial grid manager and sync layer updates for new node types
- Wall spatial grid refinements

### Viewer enhancements
- **Item light system** — new pooled lighting system for item nodes
- **Perf monitor** — built-in performance overlay component
- **Post-processing** — updated effects pipeline
- **Selection manager** — improved multi-select and hover behavior
- Roof segment renderer with material support
- Item renderer improvements
- Site renderer updates
- Wall cutout refinements

### Other
- New `layers.ts` utility for render layer management
- R3F type declarations (`r3f.d.ts`)
- Node event hook additions
- Viewer store extensions

### Packages
- `@pascal-app/core@0.2.0` — [npm](https://www.npmjs.com/package/@pascal-app/core/v/0.2.0)
- `@pascal-app/viewer@0.2.0` — [npm](https://www.npmjs.com/package/@pascal-app/viewer/v/0.2.0)

### Install
```bash
npm install @pascal-app/core@0.2.0 @pascal-app/viewer@0.2.0
```