Add the B&W HIGH CONTRAST film sim next to ACRIPES

A second black-and-white stock, so it gets its own baseFilter rather than
borrowing Acros': the PHOTO STYLE chips are keyed by baseFilter and the two
greys have to sit side by side.

The look is the B&W MIX plus a push at both ends. The mix rides the matrix — a
non-BT.709 row set (0.38/0.56/0.06, identical rows, sum 1.00) so a red roof
reads bright, a blue sky deep, and the separation is contrast before any curve.
The push rides FILM_TONE (shadow -0.32, highlight +0.26) so the ends move
without touching the midtones, and the midtone slope is SIM_CONTRAST_BIAS (4
contrast units). Every knob still opens at neutral: a sim is colour and tone
only.

Both B&W stocks being mono is now asked once, through isMonochromeBase, so the
colour-only stages (saturation, white balance, the R/B fine-tune) and the
chrome/hue-mixer gate can never half-apply to one of them.

Mirrors the web app's rail (c403dd0).

src/utils/defaultRecipes.ts

@@ -45,6 +45,11 @@ export const FILM_SIMS: FilmSim[] = [
   { id: 'sim-astia', name: 'ASTIPES', baseFilter: 'astia', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-eterna', name: 'ETERNIPES', baseFilter: 'eterna', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-acros', name: 'ACRIPES', baseFilter: 'monochrome', adjustments: { ...DEFAULT_ADJUSTMENTS, grain: 3 } },
+  // Acros taken through a warm filter, then pushed at both ends: the mix (red
+  // up, blue down) rides the matrix, the end push rides FILM_TONE, and the
+  // midtone slope the stock owns is SIM_CONTRAST_BIAS in colorUtils — never an
+  // `adjustments` value, so every knob still opens at neutral.
+  { id: 'sim-bw-high-contrast', name: 'B&W HIGH CONTRAST', baseFilter: 'mono-high-contrast', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   // The rangefinder digital look (M/Q/SL) is not a film stock, so it ships as its own
   // pair instead of one look that has to compromise:
   //   CLASSIC — the stock character: deep solid darks, natural shadows, rich but