Canvas events

[techniq]

Investigate using Flatbush as a library/technique to add events when using <Canvas>, as well as general color picking or quadtree

• Flatbush
  • https://github.com/mourner/flatbush
  • https://observablehq.com/@martgnz/using-flatbush-for-faster-canvas-maps
  • https://observablehq.com/@luissevillano/using-flatbush-for-faster-hover-events-in-canvas-maps
• Color picking
  • https://blocks.roadtolarissa.com/veltman/f539d97e922b918d47e2b2d1a8bcd2dd
  • https://observablehq.com/@camargo/canvas-picking-with-a-hidden-canvas
  • https://observablehq.com/@no-use-tech/canvas-renderer
• Quadtree
  • https://blocks.roadtolarissa.com/veltman/1b43f61887e89c371f1c8c73341540a3