fix: render consultation replies and typed tool activity

tests/e2e/fixtures/teacher-discussion-api.ts

@@ -11,6 +11,14 @@ const samples: Record<string, TeacherDiscussionContent> = {
 const scenario = new URLSearchParams(location.search).get('kind') ?? 'ideas';
 let current: TeacherTopic = { schemaVersion: 1, revision: 1, id: 'discussion-fixture', accountId: 'fixture', projectId: 'fixture', sourceConversationId: 'project', definition, version: 1, createdAt: 'now', updatedAt: 'now', requests: Array.from({ length: 8 }, (_, i) => ({ id: `r${i}`, text: i === 7 ? '我还没想好，我们边聊边想。' : '我希望这个游戏更有意思。', references: [], createdAt: 'now', sourceCursor: { workerGeneration: 0, seq: i }, sourceCapturedAt: 'now', includedSourceMessageIds: [], omittedMessages: 0, status: 'completed', response: i === 7 ? '可以，我们先把已经想到的放在一起。哪里还不确定，就留着继续聊。' : '先从你最在意的一个小地方开始想。', ...(scenario === 'ordinary' && i === 7 ? { suggestedQuestions: ['有什么好玩的想法？'] } : {}) })), ...(samples[scenario] ? { discussion: { id: 'tool', revision: 1, status: 'active', content: structuredClone(samples[scenario]), ...(scenario === 'structure' ? { previousIdeas: structuredClone(samples.ideas) as Extract<TeacherDiscussionContent, { kind: 'ideas' }> } : {}) } } : {}) };
 const stream = Object.assign(new EventTarget(), { close() {}, onerror: null, onopen: null });
+if (scenario === 'rich-text') {
+  current.requests = [{
+    ...current.requests[0], text: '帮我看看项目和最近的讨论',
+    response: '## 项目建议\n\n**先核对已有设计**，再决定下一步。\n\n- 检查入口文件\n- 保留当前玩法\n\n| 文件 | 作用 | 需要确认 |\n| --- | --- | --- |\n| src/main.ts | 初始化项目 | 游戏循环与计时 |\n| public/assets | 图片资源 | 构建后路径是否可用 |\n\n```js\nconst message = "保留字符串里的\\n，不把它变成实际换行";\nconst resourcePath = "/assets/" + "very-long-file-name-".repeat(15);\n```\n\n运动距离：$s = vt$。\n\n![项目截图](https://example.com/teacher-preview.png)\n\n[项目说明](https://example.com/readme)\n\n> 先验证观察到的现象。',
+    discussionError: '这次整理没有完成，先保留原来的内容。',
+    unparsedResponse: '{"reply":"正文已保留","tool":{"kind":"structure",',
+  }];
+}
 let timer: ReturnType<typeof setTimeout> | undefined;
 const snapshot = () => { current.revision++; stream.dispatchEvent(new MessageEvent('snapshot', { data: JSON.stringify(current) })); };
 export const teacherApi = {