nx_enginelab_golden.nx

nx_enginelab_golden.nx -- GOLDEN-IMAGE REGRESSION for the engine instrument (the O3DE class). WHY THIS IS ITS OWN MODULE, EXTRACTED FROM nx_enginelab_lib ON 2026-08-28. It started life inside the core spine, and that was wrong for a measurable reason rather than a stylistic one: the spine is frames, CPU zones, GPU queue slices, draw calls, allocations and lock waits -- ALL PURE INTEGER, and deliberately so, because the natural first consumer of an engine instrument is the engine, and this estate's engines compile to wasm. Golden-image comparison is the one row that needs to read a PNG, so keeping it in the core made EVERY consumer of the integer spine import nx_visual_diff and with it a PNG decoder, for a capability most of them will never call. A CAPABILITY THAT TAXES EVERY CONSUMER FOR A FEATURE MOST OF THEM NEVER CALL BELONGS IN ITS OWN MODULE -- and the cost is not theoretical: it is paid by whichever organ adopts the spine first. Nothing about the behaviour changed in the move. el_golden is byte-for-byte the same function, its refusal still propagates, and the gate that proves it is unchanged -- which is exactly why the extraction is provable: the gate must stay 38 of 38 GREEN across it, and a same-verdict run on a smaller closure is the whole evidence for the split. license_tier: ORIGINAL No hardware writes (Rule 26).