Filter 32015 chunks were written with the streaming encoder
(zstd::encode_all), whose frames carry no content size. The registered
HDF5 Zstandard filter (H5Zzstd.c, libhdf5 + hdf5plugin) sizes its output
from ZSTD_getFrameContentSize and fails on such frames, so h5py could not
read our zstd datasets ("filter returned failure during read"). Compress
with the one-shot API, which records the size.
Tests: zstd_frames_record_content_size (content size was None before),
hdf5plugin_reads_our_zstd (ignored interop test; failed before).
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>