fix(admin): harden clothing/pets/effects/clone imports

Align grids on data.items, only treat SSE done as success, hard-fail
clothing sets when libs fail, and add Cancel via AbortController.

Co-authored-by: Cursor <[email protected]>

src/app/admin/import/furni/import-furni-client.tsx

@@ -336,7 +336,7 @@ export function ImportFurniClient() {
 					setError(data.error || "Failed to load");
 					return;
 				}
-				const loadedItems = data.item || [];
+				const loadedItems = data.items || [];
 				setItems(loadedItems);
 				setMeta(data.meta || null);
 				setSelected(new Set());