Fix useFilters hook to match API response structure

Remove nested .filters access to match updated FiltersResponse type.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

nextjs-app/hooks/useFilters.ts

@@ -19,10 +19,10 @@ export function useFilters() {
   );
 
   return {
-    filters: data?.filters,
-    localAuthorities: data?.filters.local_authorities || [],
-    schoolTypes: data?.filters.school_types || [],
-    years: data?.filters.years || [],
+    filters: data,
+    localAuthorities: data?.local_authorities || [],
+    schoolTypes: data?.school_types || [],
+    years: data?.years || [],
     isLoading,
     error,
   };