CCTV frames and the Street View fallback accept only JPEG, PNG, GIF, WebP and
AVIF, parsed from the media type essence and sent under the canonical type;
any other type is cancelled and falls through to the next fallback as a
failed upstream does. Live media must match its feed kind (video/mp4,
video/webm, or multipart/x-mixed-replace with a boundary) before the camera
is reported healthy or any byte is relayed, and its redirects now stay on the
registered origin like frames. Every /api/cctv route uses the same-site gate.
The GBFS proxy relays only bodies that parse as JSON, re-serialized under a
fixed application/json type.