Frigate has cross-camera snapshot disclosure via unrestricted timeline IDs and missing authorization in /api/events/{event_id}/snapshot-clean.webp

Frigate is a network video recorder (NVR) with realtime local object detection for IP cameras. In version 0.17.0, a low-privilege authenticated user restricted to one camera can access snapshots from other cameras. This is possible through a chain of two authorization problems: `/api/timeline` returns timeline entries for cameras outside the caller's allowed camera set, then `/api/events/{event_id}/snapshot-clean.webp` declares `Depends(require_camera_access)` but never actually validates `event.camera` after looking up the event. Together, this allows a restricted user to enumerate event IDs from unauthorized cameras and then fetch clean snapshots for those events. Version 0.17.1 fixes the issue.