Add e2e test for balanced smart context mode (#1901)

<!-- CURSOR_SUMMARY -->
> [!NOTE]
> Adds an e2e test for the balanced Smart Context mode with
corresponding ARIA and request payload snapshots.
> 
> - **Tests**:
> - Add `e2e-tests/smart_context_balanced.spec.ts` to exercise Pro Modes
dialog, set Smart Context to `balanced`, send `[dump]`, and snapshot
server dump and messages.
>   - Add snapshots:
> -
`e2e-tests/snapshots/smart_context_balanced.spec.ts_smart-context-balanced---simple-1.aria.yml`
> -
`e2e-tests/snapshots/smart_context_balanced.spec.ts_smart-context-balanced---simple-1.txt`
(captures request body/options).
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
66bf07057ded2a6afb328b7de01c821ab6a0fca8. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

<!-- This is an auto-generated description by cubic. -->
## Summary by cubic
Added an end-to-end test for the “balanced” Smart Context mode to verify
the Pro Modes dialog switches to balanced and the mode is applied. The
test sends a [dump] prompt, snapshots the server request and messages
(ARIA + text), and is skipped on Windows.

<sup>Written for commit 66bf07057ded2a6afb328b7de01c821ab6a0fca8.
Summary will update automatically on new commits.</sup>

<!-- End of auto-generated description by cubic. -->

e2e-tests/smart_context_balanced.spec.ts

@@ -0,0 +1,15 @@
+import { testSkipIfWindows } from "./helpers/test_helper";
+
+testSkipIfWindows("smart context balanced - simple", async ({ po }) => {
+  await po.setUpDyadPro({ autoApprove: true });
+  const proModesDialog = await po.openProModesDialog({
+    location: "home-chat-input-container",
+  });
+  await proModesDialog.setSmartContextMode("balanced");
+  await proModesDialog.close();
+
+  await po.sendPrompt("[dump]");
+
+  await po.snapshotServerDump("request");
+  await po.snapshotMessages({ replaceDumpPath: true });
+});