feat(09-01): add classification API route, client hook, badge component, and setup detail wiring

- Add PATCH /:id/items/:itemId/classification endpoint with Zod validation
- Add apiPatch helper to client API library
- Add useUpdateItemClassification mutation hook
- Add classification field to SetupItemWithCategory interface
- Create ClassificationBadge click-to-cycle component (base/worn/consumable)
- Wire ClassificationBadge into setup detail page item grid
- Add integration tests for PATCH classification route (valid + invalid)

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

src/client/components/ClassificationBadge.tsx

@@ -0,0 +1,30 @@
+const CLASSIFICATION_LABELS: Record<string, string> = {
+	base: "Base Weight",
+	worn: "Worn",
+	consumable: "Consumable",
+};
+
+interface ClassificationBadgeProps {
+	classification: string;
+	onCycle: () => void;
+}
+
+export function ClassificationBadge({
+	classification,
+	onCycle,
+}: ClassificationBadgeProps) {
+	const label = CLASSIFICATION_LABELS[classification] ?? "Base Weight";
+
+	return (
+		<button
+			type="button"
+			onClick={(e) => {
+				e.stopPropagation();
+				onCycle();
+			}}
+			className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-gray-100 text-gray-600 hover:bg-gray-200 transition-colors cursor-pointer"
+		>
+			{label}
+		</button>
+	);
+}