v0.5.1

Changed

• HDF5 reads are now rayon-parallel (rust-hdf5 0.3.0 with the parallel
  feature: parallel chunk decode — deflate inflate + chunk gather). Read sits on
  the critical path of the streaming reconstruction (each row-chunk re-decodes
  the whole projection-chunked dataset), so this is a large end-to-end win. On a
  1200×512×512 fbp streaming reconstruction (1 GPU): gzip-chunked input
  73.5 s → 4.3 s (17×), uncompressed-chunked 9.5 s → 3.1 s (3.1×);
  reconstruction output is byte-for-byte identical (the decode is deterministic).