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/page.tsx

@@ -1,6 +1,7 @@
 import {
 	BadgeCheck,
 	Cat,
+	ClipboardCheck,
 	Copy,
 	Dumbbell,
 	ImageIcon,
@@ -76,6 +77,12 @@ export default async function ImportPage() {
 			icon: ImageIcon,
 			description: t("repairIconsDescription"),
 		},
+		{
+			href: "/admin/import/audit",
+			label: t("audit"),
+			icon: ClipboardCheck,
+			description: t("auditDescription"),
+		},
 	] as const;
 
 	return (