docs(KB-056): add inline comment explaining GET /models empty array behavior

- Document why /models returns 200 with empty array instead of 404

- Clarify frontend empty state handling expectation

packages/dashboard/src/routes.ts

@@ -2143,6 +2143,8 @@ async function refreshPrInBackground(store: TaskStore, taskId: string, currentPr
 function registerModelsRoute(router: Router, modelRegistry?: ModelRegistryLike): void {
   router.get("/models", (_req, res) => {
     try {
+      // Always return 200 with empty array instead of 404 when no models available.
+      // This ensures the frontend can handle empty states gracefully.
       if (!modelRegistry) {
         res.json([]);
         return;