fix: cover httpx disconnect family in transient error set

adapters/llm.py

@@ -179,7 +179,10 @@ def _is_transient_error(exc: Exception) -> bool:
     返回:
         True 表示可重试，False 表示不可重试。
     """
-    if isinstance(exc, (httpx.ConnectError, httpx.ReadTimeout, httpx.WriteTimeout)):
+    # 两族基类覆盖断连族：TimeoutException（ConnectTimeout/ReadTimeout/WriteTimeout/PoolTimeout）
+    # 与 TransportError（ConnectError/ReadError/RemoteProtocolError 等）。
+    # 注意 HTTPStatusError 非 TransportError 子类，401/403 致命分支不受影响。
+    if isinstance(exc, (httpx.TimeoutException, httpx.TransportError)):
         return True
     if isinstance(exc, httpx.HTTPStatusError):
         return exc.response.status_code in _TRANSIENT_STATUS_CODES

tests/unit/test_governed_llm.py

@@ -259,6 +259,16 @@ async def test_qwen_thinking_stripped():
     assert thinking2 == ""
 
 
+def test_transient_covers_disconnect_family():
+    """瞬时错误清单覆盖断连族（RemoteProtocolError/ReadError/ConnectTimeout/PoolTimeout）。"""
+    from adapters.llm import _is_transient_error
+
+    assert _is_transient_error(httpx.RemoteProtocolError("peer reset"))
+    assert _is_transient_error(httpx.ReadError("read"))
+    assert _is_transient_error(httpx.ConnectTimeout("ct"))
+    assert _is_transient_error(httpx.PoolTimeout("pt"))
+
+
 @pytest.mark.asyncio
 async def test_truncated_stream_without_done_raises():
     """SSE 流耗尽但未收 [DONE] → _SseAnomaly（进重试，不当成功）。"""