The /photos/{id}/proxy endpoint (added in 1096854) caches transcoded
RAW/HEIC WebPs at /data/proxies/{id}.webp, but the compose file had no
volume mount for that path — files would be lost on every container
restart, forcing repeated full-resolution decodes. Adding a named
volume to both backend and worker so the cache survives restarts.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
