refactor: add useFormatters hook to reduce boilerplate across 14 components

Created useFormatters() combining useWeightUnit + useCurrency + formatWeight/formatPrice
into a single hook returning weight(grams) and price(cents) bound functions plus
raw unit and currency values. Updated all 14 consumer files to use the new hook,
removing the repeated 4-import + 2-hook-call pattern from each.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/client/hooks/useFormatters.ts

@@ -0,0 +1,14 @@
+import { formatPrice, formatWeight } from "../lib/formatters";
+import { useCurrency } from "./useCurrency";
+import { useWeightUnit } from "./useWeightUnit";
+
+export function useFormatters() {
+	const unit = useWeightUnit();
+	const currency = useCurrency();
+	return {
+		weight: (grams: number | null) => formatWeight(grams, unit),
+		price: (cents: number | null) => formatPrice(cents, currency),
+		unit,
+		currency,
+	};
+}