fix: render consultation replies and typed tool activity

tests/unit/teacher-discussion.test.ts

@@ -176,6 +176,20 @@ describe('teacher discussion model envelope', () => {
       .toEqual({ reply: '柯基、冒险和菜园都是好点子。', quickReplies: [] });
   });
 
+  it.each([
+    '[项目说明](https://example.com/readme)\n\n先看已有设计。',
+    '[1, 2, 3]',
+    '[{"reply":"普通数组示例"}]',
+    '```json\nnot valid json\n```',
+    '{"scripts":{"dev":"vite"},"name":"flybot"}',
+    '项目配置可以这样写：\n\n```json\n{"name":"flybot","scripts":{"dev":"vite"}}\n```',
+    '```json\n[{"id":1,"label":"入口"}]\n```',
+    '{"example":{"reply":"这是数据字段，不是回答协议"}}',
+    '```js\nconst example = {"reply":"代码示例"};\n```',
+  ])('preserves Markdown links and JSON examples as readable content: %s', raw => {
+    expect(parseTeacherDiscussionReply(raw)).toEqual({ reply: raw, quickReplies: [] });
+  });
+
   it('distinguishes an absent tool from an explicit null and supports a tool-only envelope', () => {
     expect(parseTeacherDiscussionReply('{"reply":"这轮只解释一下。"}'))
       .toEqual({ reply: '这轮只解释一下。', quickReplies: [] });
@@ -213,8 +227,7 @@ describe('teacher discussion model envelope', () => {
     '{"reply":"还没有说完',
     '{"tool":{"reply":"不能拿嵌套结构充当正文"},',
     '```json\n{"tool":{"secret":"raw-data"}}',
-    '```json\nnot valid json\n```',
-    '[{"reply":"不是合法 envelope"}]',
+    '```makelore-teacher-discussion\nnot valid json\n```',
     '{"reply":13,"tool":{"kind":"html"}}',
     '```json\n{"reply":"结束"}\n```\n```json\n{"reply":"第二个"}\n```',
   ])('never exposes malformed JSON as the student reply: %s', raw => {