修复流式 Markdown 错误边界恢复

累计文本变化时清除错误边界状态并重新尝试 Markdown 渲染。

新增首次渲染失败后随文本更新恢复的回归测试。

apps/ai-game-creator-shell/src/components/ChatMarkdownMessage/index.tsx

@@ -18,7 +18,7 @@ type MarkdownErrorBoundaryState = {
   hasError: boolean;
 };
 
-class MarkdownErrorBoundary extends Component<
+export class MarkdownErrorBoundary extends Component<
   MarkdownErrorBoundaryProps,
   MarkdownErrorBoundaryState
 > {
@@ -32,6 +32,15 @@ class MarkdownErrorBoundary extends Component<
     // Keep the original message visible without logging its potentially sensitive content.
   }
 
+  componentDidUpdate(prevProps: MarkdownErrorBoundaryProps) {
+    if (
+      this.state.hasError &&
+      prevProps.fallbackText !== this.props.fallbackText
+    ) {
+      this.setState({ hasError: false });
+    }
+  }
+
   render() {
     if (this.state.hasError) {
       return (

apps/ai-game-creator-shell/tests/ChatMarkdownMessage.test.tsx

@@ -1,9 +1,19 @@
 // @vitest-environment jsdom
 
 import { render } from '@testing-library/react';
-import { describe, expect, it } from 'vitest';
+import { describe, expect, it, vi } from 'vitest';
 
-import { ChatMarkdownMessage } from '../src/components/ChatMarkdownMessage';
+import {
+  ChatMarkdownMessage,
+  MarkdownErrorBoundary,
+} from '../src/components/ChatMarkdownMessage';
+
+function FailingChild({ shouldThrow }: { shouldThrow: boolean }) {
+  if (shouldThrow) {
+    throw new Error('transient render failure');
+  }
+  return <span>markdown recovered</span>;
+}
 
 describe('ChatMarkdownMessage', () => {
   it('渲染 assistant 的 GFM 内容与代码块', () => {
@@ -95,6 +105,31 @@ describe('ChatMarkdownMessage', () => {
     expect(code?.className).not.toContain('rounded');
   });
 
+  it('累计文本变化后可从 Markdown 错误回退中恢复', () => {
+    const consoleError = vi
+      .spyOn(console, 'error')
+      .mockImplementation(() => {});
+    try {
+      const { container, rerender } = render(
+        <MarkdownErrorBoundary fallbackText="partial">
+          <FailingChild shouldThrow />
+        </MarkdownErrorBoundary>,
+      );
+
+      expect(container.textContent).toBe('partial');
+
+      rerender(
+        <MarkdownErrorBoundary fallbackText="complete">
+          <FailingChild shouldThrow={false} />
+        </MarkdownErrorBoundary>,
+      );
+
+      expect(container.textContent).toBe('markdown recovered');
+    } finally {
+      consoleError.mockRestore();
+    }
+  });
+
   it('保留流式 assistant 文本并标记 streaming 状态', () => {
     const { container } = render(
       <ChatMarkdownMessage