refactor(font): keep @tanstack out of the entity public API barrel

Extract NonRetryableError into its own tanstack-free module and drop the
./api re-export from the Font slice barrel. Importing $entities/Font no
longer transitively loads @tanstack/query-core or constructs the QueryClient
singleton via the ./api and ./lib (errors) chains — light consumers (domain,
types, consts) and unit specs stop paying for TanStack.

Note: ./ui still pulls the stores; addressed separately.

src/features/FilterAndSortFonts/api/filters/filters.ts

@@ -9,7 +9,7 @@
 
 import { api } from '$shared/api/api';
 import { API_ENDPOINTS } from '$shared/api/endpoints';
-import { NonRetryableError } from '$shared/api/queryClient';
+import { NonRetryableError } from '$shared/api/nonRetryableError';
 
 const PROXY_API_URL = API_ENDPOINTS.filters;