fix(agent-browser): restore bounded presentation lifecycle

tests/unit/pi-extension-host.test.ts

@@ -5,6 +5,8 @@ import { tmpdir } from 'node:os';
 import path from 'node:path';
 import { afterEach, describe, expect, it } from 'vitest';
 import { PiManagedExtensionHost } from '../../electron/coding-runtime/pi/extension-host';
+import { AgentBrowserFault } from '../../electron/agent-browser/fault';
+import type { PiProductTools } from '../../electron/coding-runtime/pi/product-tools';
 import { PiProjectWriteLeaseCoordinator } from '../../electron/coding-runtime/pi/write-lease';
 import {
   PiSubagentChildError,
@@ -35,6 +37,42 @@ async function post(
 }
 
 describe('managed Pi extension bridge', () => {
+  it('preserves structured Agent Browser faults across the product bridge', async () => {
+    const root = await mkdtemp(path.join(tmpdir(), 'makelore-pi-extension-browser-fault-'));
+    roots.push(root);
+    const host = new PiManagedExtensionHost();
+    hosts.push(host);
+    host.configureProductTools({
+      beginRun: async () => undefined,
+      execute: async () => {
+        throw new AgentBrowserFault(
+          'VIEWPORT_NOT_READY',
+          '开发浏览器显示区域没有及时准备好。',
+          true,
+          7,
+        );
+      },
+    } as unknown as PiProductTools);
+    const registration = await host.registerWorker({
+      conversationId: 'conversation-a', generation: 1, projectId: 'project-a',
+      projectPath: root, extensionsDir: root,
+    });
+    await host.bindRun('conversation-a', 1, 'run-a');
+
+    const response = await post(registration, {
+      action: 'product.invoke', conversationId: 'conversation-a', workerGeneration: 1,
+      runId: 'run-a', resourceId: 'browser-a', toolName: 'agent_browser', input: { action: 'status' },
+    });
+
+    expect(response.status).toBe(400);
+    await expect(response.json()).resolves.toEqual({
+      code: 'VIEWPORT_NOT_READY',
+      error: 'VIEWPORT_NOT_READY: 开发浏览器显示区域没有及时准备好。',
+      retryable: true,
+      generation: 7,
+    });
+  });
+
   it('single-flights the shared managed extension for concurrent worker registration', async () => {
     const root = await mkdtemp(path.join(tmpdir(), 'makelore-pi-extension-concurrent-'));
     roots.push(root);