chore: import upstream snapshot with attribution

showcase/integrations/langgraph-python/tests/e2e/reasoning-default.spec.ts

@@ -0,0 +1,41 @@
+import { test, expect } from "@playwright/test";
+
+// QA reference: qa/reasoning-default.md
+// Demo source: src/app/demos/reasoning-default/page.tsx
+//
+// This cell does NOT override the `reasoningMessage` slot. CopilotKit's
+// built-in `CopilotChatReasoningMessage` renders the reasoning as a
+// collapsible card. The page exposes a "Show reasoning" suggestion pill
+// whose message matches the aimock fixture in showcase/aimock/d5-all.json,
+// so streaming is deterministic in CI.
+
+test.describe("Reasoning: Default", () => {
+  test.setTimeout(120_000);
+
+  test.beforeEach(async ({ page }) => {
+    await page.goto("/demos/reasoning-default");
+  });
+
+  test("page renders without errors", async ({ page }) => {
+    await expect(
+      page.locator('[data-testid="copilot-chat-input"]'),
+    ).toBeVisible();
+  });
+
+  test("Show reasoning pill renders a reasoning-role message", async ({
+    page,
+  }) => {
+    const pill = page.getByRole("button", { name: /Show reasoning/i }).first();
+    await expect(pill).toBeVisible({ timeout: 30_000 });
+    await pill.click();
+
+    // The cell uses CopilotKit's default `CopilotChatReasoningMessage`,
+    // which doesn't emit a testid — its visible signal is the
+    // streaming/complete header label ("Thinking…" while streaming,
+    // "Thought for …" once complete). Asserting on either label proves
+    // the reasoning collapsible mounted.
+    await expect(page.getByText(/Thinking…|Thought for/i).first()).toBeVisible({
+      timeout: 60_000,
+    });
+  });
+});