Memory64 moved the browser ceiling and exposed an ABI gap

A 32-bit WebAssembly heap put the browser playground near a 4 GB ceiling. With weights and AdamW state, that limited the fp32 model size to roughly 250 million parameters. Compiling the same C++ source with Memory64 and BigInt support changed the pointer width. One measured run allocated 473,244,160 parameters in 3.7 seconds, completed a training...