Both builds and imagor now crop the same region, a gif is bounded by its
declared frames, the posted body by THUMBNAILS_MAX_INPUT_IMAGE_FILE_SIZE and an
image extracted from a container by the configured input size. The s3 cache
reads a miss where minio reports it.
The push endpoint's HTTP behaviour is asserted in the parity suite now, where
imagor answers the same request, so 41 duplicated service specs are gone and
the 32 that remain are what a non-default config or a helper decides.
The push endpoint takes an empty filters segment, ignores an image key behind the box and computes a side given as 0 from the other one, all measured against both imagors and pinned in the parity suite. Plus the review leftovers: no em dashes, the request test on ginkgo, comments that contradicted the code, one stat for Head and generate, one thumbnail handler, the gif fit-in rounding of vips, and the new env names last so they win.