Pascal Editor ships browser-based 3D building editor

This looks less like a demo and more like the skeleton of browser-native CAD-lite software. The graphics stack is interesting, but the real moat will be whether the editing rules feel safe, fast, and predictable.

• –The `core`/`viewer`/`editor` split is the right architecture for a complex 3D authoring app, because it keeps geometry, rendering, and UI logic separable.
• –The node hierarchy maps to real spatial workflows, so the product feels aimed at architecture, facilities, or digital-twin use cases rather than generic scene building.
• –Collision checks, placement validation, and custom camera control are the hard parts that decide whether users trust the editor.
• –IndexedDB persistence plus undo/redo make it feel like actual design software instead of a throwaway visualizer.
• –If the release cadence stays healthy, this could become a strong open-source base for browser-based spatial tooling.