nx_gen_cid_gate.nx

nx_gen_cid_gate.nx -- REFEREE for the GALLERY CID CANON (debt 1785881333 / 1785881657). WHAT IT PROTECTS. The gallery CID is NOT a hash of the pixels, despite the name: it is a hash of a CANONICAL FORM built from the PNG's tEXt fields. Twice on 2026-08-04 that canon was missing a field that genuinely changes the image, and the consequence each time was SILENT DATA LOSS -- the second render collided onto the first cid and gp_one's openat_wr truncated the earlier blob: * resolution: 512x512 (md5 a9fa671a) then 768x1024 under the SAME cid -> the 512 image was gone. * cfg_scale: cfg 1.0 (md5 f10849c2) vs 5.0 (md5 6471d466), two different pictures, ONE cid. Fixed by adding `size` and then `args` (the exact generator-facing argument string) to the canon. ★WHY A GATE AND NOT JUST THE FIX: the second collision existed the whole time the first was being celebrated as fixed. Nothing was checking, so a narrower trigger survived. This gate encodes the INVARIANT rather than the two instances: ANY tEXt field that differs must move the cid. ★HERMETIC AND GPU-FREE. It builds tiny synthetic PNGs in memory and drives the REAL png_insert_genrec + nx_store_ingest_compute_cid -- the same code the daemon runs. No render, no engine, no network, so it is safe on any cadence. (A gate that needs a GPU is a gate nobody runs.) license_tier: ORIGINAL expect_exit: 0 module: nishi-core.gen.cidgate