chore: stabilize Zhinian pilot delivery

tests/unit/chat-message-utils.test.ts

@@ -17,4 +17,18 @@ describe('chat message display cleanup', () => {
 
     expect(extractText({ role: 'user', content })).toBe('');
   });
+
+  it('hides injected knowledge context from user display text', () => {
+    const content = [
+      '帮我总结一下这份资料',
+      '',
+      '[知识库上下文]',
+      '用户已选择在本轮对话中使用当前组织空间知识库。',
+      '',
+      '## 内部资料.docx',
+      '这是一段不应该出现在用户气泡里的知识库正文。',
+    ].join('\n');
+
+    expect(extractText({ role: 'user', content })).toBe('帮我总结一下这份资料');
+  });
 });