Move 74 seq-*.tiff test images to tests/images/seq/ and embed a CRC32
hash of the full decoded output (dimensions, color type, sample data)
as the last filename segment. Replace 75 individual test functions with
one generic verify_all_seq_images test that decodes each file and
validates its hash against the filename.
This catches byte-order, bit-alignment, stride, padding, and value
errors that sum-based tests would miss (e.g., swapped pixels preserve
the sum but change the hash). Adding new test images only requires
dropping a correctly-named file in seq/ — no test code changes needed.
Lilith River
43cfc5bc3a