nx_nxfh_lib.nx

nx_nxfh_lib.nx -- shared NXFH1 text-hex framebuffer codec (LIB, no main). license_tier: ORIGINAL WHY A LIB (DRY, rule 15): the NXFH1 parser lived ONLY inside nx_frame_score.nx (an organ with a main, so nothing could import it); the moment a second consumer existed (nx_frame_score2 + gates) copies #2 and #3 were about to happen. This is the extraction. The DEPLOYED nx_frame_score keeps its private copy untouched -- this task builds a new instrument, it does not touch the live one. FORMAT NXFH1 (deliberately TEXT so it travels the fs-write lane safely; raw binary through JSON-string tooling is the proven corruption path): line 1: "NXFH1 <w> <h>\n" then w*h pixels as 6 lowercase hex chars each (rrggbb), any whitespace between pixels ignored. Decoded pixel layout r | g<<8 | b<<16 = the critic fb layout. CONTRACT: nxl_load REFUSES (returns 0) on missing file, bad magic, junk bytes, short/overlong pixel stream -- a truncated capture must never be scored as a dark frame. nxl_dump is the writer; a writer is only tested by a read-back (banked law), which nx_craft_capture_gate enforces.