Written for review before iris's render core changes. Covers the bindless
binding-array problem, the gpu-probe measurements (emulator and sourced
real-hardware findings), what growth already costs today in the current
code, the egui_wgpu/Vello prior art, and the recommendation with its open
questions -- not yet implemented.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>