CHANGELOG: upgrade notes (changed read results for max-shape files, saturating conversions, new writer errors, format-crate API changes) and the reader/writer correctness fixes. known-issues: the silent-wrong-data table with before/after sweep numbers, the gaps still open, and a correction to the Extensible Array entry, which said files we wrote were unaffected. CLAUDE.md: clawhdf5-gpu is vector distance computation, not I/O, and clawhdf5-filters holds only deflate backends (no Blosc). Also a facade test that libhdf5's 20-bit N-Bit float test data reads as libhdf5's values. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>