Add installment calculator and Latin digits in English product text.

Wire the product CTA to store-loan-methods calculate so shoppers can pick a term and see the plan, and render English model runs under Montserrat so fanum fonts stop painting 0-9 as Persian digits.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/ui/ProductCard.tsx

@@ -1,5 +1,6 @@
 import Image from "next/image";
 import Link from "next/link";
+import MixedText from "@/components/MixedText";
 import { formatPrice, toFaDigits } from "@/lib/format";
 import type { ProductCardData } from "@/lib/types";
 
@@ -34,7 +35,7 @@ export default function ProductCard({ product }: { product: ProductCardData }) {
       </span>
 
       <span className="clamp-2 mb-3 min-h-[42px] px-1 text-[12.5px] leading-[21px] text-ink-soft">
-        {title}
+        <MixedText>{title}</MixedText>
       </span>
 
       {/* The old-price line always occupies its row — rendered empty when there