nx_jpeg_pgm_dump_test.nx

nx_jpeg_pgm_dump_test.nx -- PROOF dumper for the bits-up JPEG decoder. Reads the real source.jpg staged in the proof folder, decodes it through nx_jpeg_decode_luma (the SAME decode path the ASCII renderer uses), and writes the full-resolution luma (Y) plane as a binary PGM (P5) so an INDEPENDENT decoder (Windows GDI+ via PowerShell) can be diffed against it pixel-for-pixel. This exists because "assertions PASS" is not proof. The PGM this writes is compared, off-box, to a third-party decode of the same bytes; the MAE / PSNR is the proof. Asserts the decoded dimensions equal the known 239x178 (so a silent SOF mis-parse can't pass), then emits the PGM. expect_exit: 0 license_tier: ORIGINAL