Give ACRIPES a straight BT.709 ramp and end-only tone

src/utils/toneShader.ts

@@ -189,6 +189,16 @@ export interface ToneUniforms {
 const FILM_TONE: Partial<Record<BaseFilter, Partial<ToneUniforms>>> = {
   'classic-chrome': { sh: -0.28 },
   'classic-neg': { shT: [-0.018, 0.009, 0.013], hlT: [0.024, 0.008, -0.012] },
+  // Acros. A black-and-white stock IS its grey ramp, so this entry only shapes
+  // the two ENDS and leaves the middle an identity: a smooth shadow toe that
+  // reaches a true black (no film-base lift, no flat grey wash) and a highlight
+  // shoulder that stops just short of white instead of clipping a cloud to
+  // paper. Mid-tones see neither mask, so the ramp keeps every step the matrix
+  // handed over — which is what 'deep black' costs in a colour stock and does
+  // not have to cost here.
+  // Gains are TONE_SKSL's own (sh * 0.34, hl * 0.22), so -0.12 puts the toe at
+  // ~5% and -0.05 trims the top ~1%.
+  monochrome: { sh: -0.12, hl: -0.05 },
 };
 
 export function getToneUniforms(adj: ColorAdjustments, baseFilter?: BaseFilter): ToneUniforms {