The RAW/DNG extraction was only wired into processUploadedPhotos() (the
synchronous path), but real uploads queue to 'pending' and are handled by the
background worker → processPhoto(), which generated the thumbnail + dimensions
directly from the DNG (both fail) and then marked the photo 'complete' — success
with no thumbnail. Wire withProcessableImage() into processPhoto() (the live
path) and into photoReplacementService.replacePhoto() (replace-by-name), so all
three ingest paths extract the embedded JPEG preview for RAW.
Updates the processPhoto test's imageProcessor mock with the new
withProcessableImage dependency (pass-through for ordinary images).