feat(03-02): setup list page, detail page, and item picker

- Create SetupCard component with name, item count, weight, cost display
- Build setups list page with inline create form and grid layout
- Build setup detail page with category-grouped items and sticky totals bar
- Create ItemPicker component in SlideOutPanel with category-grouped checkboxes
- Add onRemove prop to ItemCard for non-destructive setup item removal
- Setup detail has delete confirmation dialog with collection safety note
- Empty states for both setup list and setup detail pages

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/client/components/SetupCard.tsx

@@ -0,0 +1,43 @@
+import { Link } from "@tanstack/react-router";
+import { formatWeight, formatPrice } from "../lib/formatters";
+
+interface SetupCardProps {
+  id: number;
+  name: string;
+  itemCount: number;
+  totalWeight: number;
+  totalCost: number;
+}
+
+export function SetupCard({
+  id,
+  name,
+  itemCount,
+  totalWeight,
+  totalCost,
+}: SetupCardProps) {
+  return (
+    <Link
+      to="/setups/$setupId"
+      params={{ setupId: String(id) }}
+      className="block w-full text-left bg-white rounded-xl border border-gray-100 hover:border-gray-200 hover:shadow-md transition-all p-4"
+    >
+      <div className="flex items-start justify-between mb-3">
+        <h3 className="text-sm font-semibold text-gray-900 truncate">
+          {name}
+        </h3>
+        <span className="ml-2 inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-700 shrink-0">
+          {itemCount} {itemCount === 1 ? "item" : "items"}
+        </span>
+      </div>
+      <div className="flex flex-wrap gap-1.5">
+        <span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-700">
+          {formatWeight(totalWeight)}
+        </span>
+        <span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-green-50 text-green-700">
+          {formatPrice(totalCost)}
+        </span>
+      </div>
+    </Link>
+  );
+}