When the viewer is hosted on a static origin (GitHub Pages, S3) it has
no backend at /api/splats. The default ?backend=auto path was issuing
a fetch every 100 ms, getting a 404, falling back to the demo, and
flooding the console with one 404 per tick. Cosmetic on the surface
but real network/CPU waste over time.
After the first 404 in auto mode, set networkDisabled=true and skip
fetch on subsequent ticks — the interval still fires but goes straight
to pickDemoFrame() so the face mesh / synthetic render path keeps
animating. Remote (?backend=<url>) and live (?live=1) modes keep
retrying so a transient outage doesn't permanently downgrade them.
Co-Authored-By: claude-flow <ruv@ruv.net>
b4c2f7d20b