feat(agents): implement grid/list view toggle and enhance filters

- Added grid and list view modes to AgentTypeList with user preference management.
- Enhanced filtering with category selection alongside existing search and status filters.
- Updated AgentTypeDetail with category badges and improved layout.
- Added unit tests for grid/list views and category filtering in AgentTypeList.
- Introduced `@radix-ui/react-toggle-group` for view mode toggle in AgentTypeList.

frontend/src/lib/api/hooks/useAgentTypes.ts

@@ -44,10 +44,10 @@ const DEFAULT_PAGE_LIMIT = 20;
 export function useAgentTypes(params: AgentTypeListParams = {}) {
   const { user } = useAuth();
 
-  const { page = 1, limit = DEFAULT_PAGE_LIMIT, is_active = true, search } = params;
+  const { page = 1, limit = DEFAULT_PAGE_LIMIT, is_active = true, search, category } = params;
 
   return useQuery({
-    queryKey: agentTypeKeys.list({ page, limit, is_active, search }),
+    queryKey: agentTypeKeys.list({ page, limit, is_active, search, category }),
     queryFn: async (): Promise<AgentTypeListResponse> => {
       const response = await apiClient.instance.get('/api/v1/agent-types', {
         params: {
@@ -55,6 +55,7 @@ export function useAgentTypes(params: AgentTypeListParams = {}) {
           limit,
           is_active,
           ...(search ? { search } : {}),
+          ...(category ? { category } : {}),
         },
       });
       return response.data;