fix(tui): surface model errors

src/tui/tui-formatters.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, it } from "vitest";
+
+import { extractTextFromMessage } from "./tui-formatters.js";
+
+describe("extractTextFromMessage", () => {
+  it("renders errorMessage when assistant content is empty", () => {
+    const text = extractTextFromMessage({
+      role: "assistant",
+      content: [],
+      stopReason: "error",
+      errorMessage:
+        '429 {"type":"error","error":{"type":"rate_limit_error","message":"This request would exceed your account\\u0027s rate limit. Please try again later."},"request_id":"req_123"}',
+    });
+
+    expect(text).toContain("HTTP 429");
+    expect(text).toContain("rate_limit_error");
+    expect(text).toContain("req_123");
+  });
+
+  it("falls back to a generic message when errorMessage is missing", () => {
+    const text = extractTextFromMessage({
+      role: "assistant",
+      content: [],
+      stopReason: "error",
+      errorMessage: "",
+    });
+
+    expect(text).toContain("unknown error");
+  });
+});
+