fix: render consultation replies and typed tool activity

tests/unit/coding-teacher.test.ts

@@ -198,6 +198,9 @@ describe('cloud coding teacher', () => {
       await vi.waitFor(async () => expect((await f.service.read(f.scope, topic.id)).requests[0].status).toBe('completed'));
       const saved = (await f.service.read(f.scope, topic.id)).requests[0];
       expect(saved.response).toBe('计数器从 42 开始。');
+      expect(saved.toolActivity).toEqual([{ id: 'parent:read-counter', name: 'read_project_file', status: 'completed' }]);
+      const restarted = await f.restart();
+      expect((await restarted.read(f.scope, topic.id)).requests[0].toolActivity).toEqual(saved.toolActivity);
       expect(saved.cloudRequestId).toBe('cloud-question');
       expect(JSON.stringify(requests[0].body)).toContain('const title');
       expect(saved.truncatedMessages).toBeGreaterThan(0);
@@ -1377,6 +1380,25 @@ describe('structured teacher service integration', () => {
 
 
 describe('project consultations with selected cloud teachers', () => {
+  it('persists malformed discussion output without putting it into future model context', async () => {
+    const f = await fixture();
+    const scope = { ...f.scope, sourceId: 'project' };
+    const selected = await f.service.create(scope);
+    const raw = '{"reply":"这段正文完整。","tool":{"privateDiagnostic":"only-in-original"';
+    f.replyWith(raw);
+    await f.service.send(scope, selected.id, {
+      requestId: crypto.randomUUID(), text: '看看项目', presentation: 'discussion-v1', sourceConversationId: f.scope.sourceId,
+    });
+    f.finish();
+    await vi.waitFor(async () => expect((await f.service.read(scope, selected.id)).requests[0].status).toBe('completed'));
+    const restarted = await f.restart();
+    const saved = await restarted.read(scope, selected.id);
+    expect(saved.requests[0]).toMatchObject({ response: '这段正文完整。', unparsedResponse: raw });
+    const compiled = compileTeacherContext(saved.definition, context, saved.requests, '继续聊', []);
+    expect(JSON.stringify(compiled.messages)).not.toContain('only-in-original');
+    expect(JSON.stringify(compiled.messages)).toContain('这段正文完整。');
+  });
+
   it.each(['local', 'yuxi'])('keeps the published identity and project tools on the %s runtime', async (runtime) => {
     const f = await fixture({ cloudTeacher: runtime === 'yuxi', mockCloud: runtime === 'yuxi' });
     const scope = { ...f.scope, sourceId: 'project' };