nx_fb_perceptual.nx

nx_fb_perceptual.nx -- per-perceptual-profile gamut packer. Additive overlay on the existing nx_framebuffer.nx (2026-05-17, preserved per Cardinal 13). Adds the per-species color packers that close the gap [[feedback-multi-species-perceptual-substrate-not-anthropocentric]] names: the substrate must never bake in human-trichromat sRGB as the default. Same input RGBA produces DIFFERENT packed bytes per perceptual profile, and the KAT in nx_fb_perceptual_test.nx asserts that parametricism is real (not cosmetic). Composes: [[NISHI_GRAPHICS_ROADMAP]] G1 (this is one of the first stones) [[feedback-multi-species-perceptual-substrate-not-anthropocentric]] (the cardinal that drives non-human profiles) [[feedback-bits-up-exceed-never-match]] (no libm, integer-only; refuses sRGB-as-default that DirectX/Vulkan/Metal carry) [[feedback-no-false-ok-substrate-honesty-audit]] (unknown profile returns HUMAN_NORMAL packed bytes deterministically; never silently corrupts; KAT asserts cross-profile differentiation) existing nx_framebuffer.nx (2026-05-17 nx_fb_pack_rgba lineage -- this is its multi-species overlay; HUMAN_NORMAL packer here intentionally returns the same bytes as nx_fb_pack_rgba so the compose surface is congruent) Scope (honest, G1): - Per-profile PACKERS for HUMAN / DOG (dichromat) / HONEYBEE / AVIAN-TETRACHROMAT / PRESERVE_ALL. - Storage is still RGBA8888 i64 cells per the existing framebuffer. G2 will introduce per-profile storage formats; G1 demonstrates the packer API parametricism without storage-format churn. - UV channel synthesis for honeybee + avian is PLACEHOLDER (255-R) called out honestly here; G2+ real UV scene sampling replaces it. Reference (absorbed clean-room, no code copied): IEC 61966-2-1 (sRGB) for HUMAN_NORMAL byte order baseline. Rec. 601 luminance coefficients (77/150/29 over 256) for dog dichromat Y' channel synthesis. Jacobs 1993 "The Distribution and Nature of Colour Vision Among Mammals" -- per-species photoreceptor count source. Goldsmith 1990 "Optimization, constraint, and history in the