Core insight: the math is matrix math. Pixels are matrices. Therefore
ANY pixel-rendering system is a computation substrate.
Three levels of abuse:
1. WebGPU (where we started) — compute shader braid sort
2. HTML5 Canvas (any web host) — ImageData + getImageData()
3. fbdev (any Linux TTY) — mmap(/dev/fb0) read/write
The TTY is a universal compute interface:
- WebGPU: needs Chrome 113+
- Canvas: needs any browser (IE9+)
- fbdev: needs any Linux
- PNG: needs any image viewer (universal)
- QR code: needs any camera (ubiquitous)
The receipt IS a PNG image. The image IS the solution.
Any web host on Earth can serve the HTML5 bundle.
Math isomorphism: QUBO_matrix ↔ pixel_brightness_matrix
This is not an encoding scheme — it's mathematical identity.
Refs: WEBGPU_PIXEL_ENCODER.md (GPU compute),
S7_SPECTRAL_BASIS.md (spherical harmonics = image spectra)
