feat: redesign weight summary legend and add currency selector

Redesign WeightSummaryCard stats from a disconnected 4-column grid to a
compact legend-style list with color dots, percentages, and a divider
before the total row. Switch chart and legend colors to a neutral gray
palette.

Add a currency selector to settings (USD, EUR, GBP, JPY, CAD, AUD) that
changes the displayed symbol across the app. This is visual only — no
value conversion is performed.

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

src/client/routes/setups/$setupId.tsx

@@ -1,7 +1,6 @@
-import { createFileRoute, useNavigate } from "@tanstack/react-router";
+import { createFileRoute, Link, useNavigate } from "@tanstack/react-router";
 import { useState } from "react";
 import { CategoryHeader } from "../../components/CategoryHeader";
-import { ClassificationBadge } from "../../components/ClassificationBadge";
 import { ItemCard } from "../../components/ItemCard";
 import { ItemPicker } from "../../components/ItemPicker";
 import { WeightSummaryCard } from "../../components/WeightSummaryCard";
@@ -11,6 +10,7 @@ import {
 	useSetup,
 	useUpdateItemClassification,
 } from "../../hooks/useSetups";
+import { useCurrency } from "../../hooks/useCurrency";
 import { useWeightUnit } from "../../hooks/useWeightUnit";
 import { formatPrice, formatWeight } from "../../lib/formatters";
 import { LucideIcon } from "../../lib/iconData";
@@ -22,6 +22,7 @@ export const Route = createFileRoute("/setups/$setupId")({
 function SetupDetailPage() {
 	const { setupId } = Route.useParams();
 	const unit = useWeightUnit();
+	const currency = useCurrency();
 	const navigate = useNavigate();
 	const numericId = Number(setupId);
 	const { data: setup, isLoading } = useSetup(numericId);
@@ -107,9 +108,18 @@ function SetupDetailPage() {
 			{/* Setup-specific sticky bar */}
 			<div className="sticky top-14 z-[9] bg-gray-50 border-b border-gray-100 -mx-4 sm:-mx-6 lg:-mx-8 px-4 sm:px-6 lg:px-8">
 				<div className="flex items-center justify-between h-12">
-					<h2 className="text-base font-semibold text-gray-900 truncate">
-						{setup.name}
-					</h2>
+					<div className="flex items-center gap-3 min-w-0">
+						<Link
+							to="/collection"
+							search={{ tab: "setups" }}
+							className="text-sm text-gray-500 hover:text-gray-700 shrink-0"
+						>
+							&larr;
+						</Link>
+						<h2 className="text-base font-semibold text-gray-900 truncate">
+							{setup.name}
+						</h2>
+					</div>
 					<div className="flex items-center gap-4 text-sm text-gray-500">
 						<span>
 							<span className="font-medium text-gray-700">{itemCount}</span>{" "}
@@ -123,7 +133,7 @@ function SetupDetailPage() {
 						</span>
 						<span>
 							<span className="font-medium text-gray-700">
-								{formatPrice(totalCost)}
+								{formatPrice(totalCost, currency)}
 							</span>{" "}
 							cost
 						</span>
@@ -219,32 +229,27 @@ function SetupDetailPage() {
 									/>
 									<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
 										{categoryItems.map((item) => (
-											<div key={item.id}>
-												<ItemCard
-													id={item.id}
-													name={item.name}
-													weightGrams={item.weightGrams}
-													priceCents={item.priceCents}
-													categoryName={categoryName}
-													categoryIcon={categoryIcon}
-													imageFilename={item.imageFilename}
-													productUrl={item.productUrl}
-													onRemove={() => removeItem.mutate(item.id)}
-												/>
-												<div className="px-4 pb-3 -mt-1">
-													<ClassificationBadge
-														classification={item.classification}
-														onCycle={() =>
-															updateClassification.mutate({
-																itemId: item.id,
-																classification: nextClassification(
-																	item.classification,
-																),
-															})
-														}
-													/>
-												</div>
-											</div>
+											<ItemCard
+												key={item.id}
+												id={item.id}
+												name={item.name}
+												weightGrams={item.weightGrams}
+												priceCents={item.priceCents}
+												categoryName={categoryName}
+												categoryIcon={categoryIcon}
+												imageFilename={item.imageFilename}
+												productUrl={item.productUrl}
+												onRemove={() => removeItem.mutate(item.id)}
+												classification={item.classification}
+												onClassificationCycle={() =>
+													updateClassification.mutate({
+														itemId: item.id,
+														classification: nextClassification(
+															item.classification,
+														),
+													})
+												}
+											/>
 										))}
 									</div>
 								</div>