crop --lossless of a non-JPEG source produces a mixed-codec pyramid (reduced levels always JPEG)

[cornish]

Summary

crop --lossless of a non-JPEG source produces an internally mixed-codec
pyramid: L0 is copied verbatim (source codec) but the re-encoded reduced levels
are always JPEG. On a JPEG 2000 SVS:

$ wsitools crop --lossless --x 4000 --y 4000 --w 8192 --h 8192 -o out.svs JP2K-33003-1.svs
$ wsitools info out.svs
  L0 ... jpeg2000     <- verbatim copy (source codec)
  L1 ... jpeg         <- re-encoded reduced level
  L2 ... jpeg
  ...

So a JPEG 2000 slide cropped losslessly becomes JPEG below L0 — a mixed-codec
pyramid the user did not ask for.

Cause

Same root cause as the lossless-crop chroma-subsampling bug (already fixed):
buildPyramidFromRaster / buildPyramidFromRasterCOGWSI (via encodeAndWriteLevel)
hardcode the JPEG encoder (jpegcodec.Factory{}), so the reduced levels are JPEG
regardless of the source / L0 codec.

Fix direction

Re-encode the reduced levels in the source codec (mirror the chroma fix that
threaded sourceJPEGSubsampling — here thread the source codec / a codec factory
into buildPyramidFromRaster*), so a JP2K source yields a uniform JP2K pyramid.
For codecs with no lossless-crop encoder, either use them or error clearly rather
than silently emitting JPEG.

Found by

The automated CLI matrix audit (scripts/qa/audit.sh, codec-uniform invariant).