Get Prisms Page

The public /prisms page payload. No auth, no per-user data, relative values only. Proxied from CAMS's serving cache (CAMS owns prism state); serves the last-good copy if CAMS is briefly unreachable.

Conditional. The page polls this so a recompute reaches a browser that is already open, and the payload is megabytes of series — so it carries an ETag over its own content and answers an unchanged poll with a 304. no-cache rather than a max-age: every request revalidates (nothing is ever served stale), but an unchanged one costs a round trip and no body.