Pointmap: drop bg-removal toggle; fg-bg is mandatory

Pointmap: drop .npy download, only offer .ply

Pointmap: expose .ply download in accordion

Pointmap: replace slow poisson-disk sphere sampling with instant Fibonacci sphere

Pointmap: full aesthetic match (Helvetica, gradient title, badges); blue camera marker at origin; polished Model3D

Add fg-bg dropdown using v1 binary segmentation TorchScript model

Initial sapiens2-pointmap Space (HF download at startup, all 4 sizes, 3D viewer)