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/messages/en.json

@@ -2494,7 +2494,9 @@
 				"sync": "Auto Sync",
 				"syncDescription": "Automatically import missing furniture from all configured sources.",
 				"repairIcons": "Repair Icons",
-				"repairIconsDescription": "Download any missing icon files for furniture already in the database."
+				"repairIconsDescription": "Download any missing icon files for furniture already in the database.",
+				"audit": "Catalog Audit",
+				"auditDescription": "Scan your catalog for missing entries, broken references, and items missing from clone sources."
 			},
 			"translations": {
 				"title": "Translations",