The PR read and wrote Halftone Pattern as `Sz ` and `Ptrn` (enum `HlfT`:
`Dt `/`Crc `/`Ln `). The reference application's Filter Gallery uses `HlSz`
for the size and a `ScrT` enum (`ScrD` dot, `ScrC` circle, `ScrL` line), so a
Halftone Pattern saved there still opened as an opaque filter, and one we saved
lost its size and pattern there without a warning. The tests built their fixture
with the same keys as the code, so they passed either way.
Now the keys match, a default Halftone Pattern (HlSz 1, Cntr 5, ScrD) opens as
{size 1, contrast 5, dot} (fails before this commit), and descriptors with the
old keys stay verbatim. The docs no longer claim reopen checks in the reference
application.
Co-authored-by: denstu473 <63150090+denstu473@users.noreply.github.com>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
