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/routes/index.tsx

@@ -1,11 +1,9 @@
 import { createFileRoute } from "@tanstack/react-router";
 import { DashboardCard } from "../components/DashboardCard";
-import { useCurrency } from "../hooks/useCurrency";
+import { useFormatters } from "../hooks/useFormatters";
 import { useSetups } from "../hooks/useSetups";
 import { useThreads } from "../hooks/useThreads";
 import { useTotals } from "../hooks/useTotals";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
 
 export const Route = createFileRoute("/")({
 	component: DashboardPage,
@@ -15,8 +13,7 @@ function DashboardPage() {
 	const { data: totals } = useTotals();
 	const { data: threads } = useThreads(false);
 	const { data: setups } = useSetups();
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 
 	const global = totals?.global;
 	const activeThreadCount = threads?.length ?? 0;
@@ -33,11 +30,11 @@ function DashboardPage() {
 						{ label: "Items", value: String(global?.itemCount ?? 0) },
 						{
 							label: "Weight",
-							value: formatWeight(global?.totalWeight ?? null, unit),
+							value: weight(global?.totalWeight ?? null),
 						},
 						{
 							label: "Cost",
-							value: formatPrice(global?.totalCost ?? null, currency),
+							value: price(global?.totalCost ?? null),
 						},
 					]}
 					emptyText="Get started"