Falsett GPU reference
flow_gpu.png was initially captured on 2026-10-04 in the actual Facett workspace on Apple M2 Pro / Metal, using egui 0.36.2 and wgpu 30.0.1. It is not a Loki or dwarf capture. The fixture pins its clock to 0.375 seconds, sci-fi theme, 900×600 points and one pixel per point. The test requires real Falsett callback frames.
Re-blessed 2026-10-04 on loki (NVIDIA GeForce RTX 5080, Vulkan, driver 595.91.07), FACETT_TEST_GPU=discrete: the M2 reference differed in 9 089 of 540 000 pixels (1.68 %, max channel delta 3, region x 8..=891, y 8..=356), one level over the tolerance. Rechecked twice on loki without UPDATE_SNAPSHOTS: within 2. The plandag and brokkrview references pass on the same card as captured (4.61 % / 0.67 % of pixels, at most 2 levels) and were left unchanged.
Compare without changing the reference:
FACETT_TEST_GPU=integrated cargo test -p facett-pipeline --features wgpu --test flow_gpuThe per-channel tolerance is 2. Only an intended, reviewed visual change should use UPDATE_SNAPSHOTS=1; other hardware comparisons remain separate validation.