fix: distinguish Gemini timeout

resources/tester/test_b01_knowledge_chat.py

@@ -1,5 +1,6 @@
 import asyncio
 
+import httpx
 import pytest
 from fastapi import HTTPException
 
@@ -65,6 +66,30 @@ def test_busy_gemini_is_retried_and_reported(monkeypatch):
     assert "요청이 몰려" in error.value.detail
 
 
+def test_gemini_timeout_is_reported(monkeypatch):
+    monkeypatch.setenv("GEMINI_API_KEY", "test-key")
+    monkeypatch.setattr(chat, "search", lambda _question: [])
+
+    class Client:
+        def __init__(self, timeout):
+            pass
+
+        async def __aenter__(self):
+            return self
+
+        async def __aexit__(self, *_args):
+            pass
+
+        async def post(self, *_args, **_kwargs):
+            raise httpx.ReadTimeout("timed out")
+
+    monkeypatch.setattr(chat.httpx, "AsyncClient", Client)
+    with pytest.raises(HTTPException) as error:
+        asyncio.run(chat.ask_knowledge_chat(chat.ChatRequest(question="일위대가가 뭐야"), {}))
+    assert error.value.status_code == 504
+    assert "시간 초과" in error.value.detail
+
+
 def test_chat_searches_all_knowledge_markdown_except_excluded_folders(monkeypatch, tmp_path):
     public = tmp_path / "original" / "법률"
     guide = tmp_path / "technical_info"