feat: add catalog audit page

Checks for:
- items_base entries without catalog_items (not purchasable)
- catalog_items referencing non-existent items_base
- Items without .nitro or icon files on disk
- Duplicate classnames
- Items missing from all configured clone sources

src/app/admin/import/audit/page.tsx

@@ -0,0 +1,23 @@
+import { redirect } from "next/navigation";
+import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
+import { AuditClient } from "./audit-client";
+
+export default async function AuditPage() {
+	const { session, permissions } = await getAdminContext();
+	if (!canAccess(permissions, PERMS.ASSETS_IMPORT, session.user.rank)) {
+		redirect("/admin");
+	}
+
+	return (
+		<div className="space-y-6">
+			<div>
+				<h1 className="text-2xl font-bold tracking-tight">Catalog Audit</h1>
+				<p className="text-muted-foreground mt-1">
+					Scan your entire furniture catalog for missing entries, broken
+					references, missing files, and items available from clone sources.
+				</p>
+			</div>
+			<AuditClient />
+		</div>
+	);
+}