test(14-01): 实现 LLM 调用的可恢复错误检测和重试逻辑

- 添加 _is_recoverable_error() 静态方法判断错误类型
- 可恢复错误: ConnectionError, Timeout, HTTPError (429/500/502/503/504)
- 不可恢复错误: 其他 HTTPError (4xx), ValidationError
- 重试逻辑: 仅对可恢复错误重试 1 次，立即重试（无延迟）
- 改进日志记录: 重试用 info 级别，降级用 warning 级别
- 降级时记录具体错误类型和消息

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_semantic_robustness.py

@@ -471,8 +471,11 @@ class TestParseFailureRetry:
         # 验证调用了两次 LLM（初始 + 1 次重试）
         assert mock_client.generate.call_count == 2
 
-        # 验证日志包含重试信息
-        assert any("重试" in record.message for record in caplog.records)
+        # 验证日志包含重试信息（可能是"重试"或"retrying"）
+        assert any(
+            "重试" in record.message or "retrying" in record.message.lower()
+            for record in caplog.records
+        )
 
     def test_validation_error_no_retry(self, caplog):
         """测试 ValidationError（Pydantic 验证失败）直接降级，不重试"""
@@ -510,8 +513,10 @@ class TestParseFailureRetry:
         assert mock_client.generate.call_count == 1
 
         # 验证日志包含验证失败信息
-        assert any("Pydantic 验证失败" in record.message or "验证失败" in record.message
-                   for record in caplog.records)
+        assert any(
+            "ValidationError" in record.message or "验证失败" in record.message
+            for record in caplog.records
+        )
 
     def test_parse_error_logs_llm_output(self, caplog):
         """测试解析失败时记录 LLM 输出片段（前 500 字符）"""
@@ -528,17 +533,17 @@ class TestParseFailureRetry:
 
         segments = [Segment(1, 0.0, 1.0, "测试")]
 
-        with caplog.at_level(logging.ERROR):
+        with caplog.at_level(logging.WARNING):
             result = strategy.segment(segments, {"title": "测试"})
 
-        # 验证日志包含 LLM 输出片段
-        error_logs = [record for record in caplog.records if record.levelno == logging.ERROR]
-        assert len(error_logs) > 0
+        # 验证日志包含 LLM 输出片段（使用 WARNING 级别）
+        warning_logs = [record for record in caplog.records if record.levelno == logging.WARNING]
+        assert len(warning_logs) > 0
 
         # 验证日志包含 LLM 输出片段信息
         assert any(
-            "LLM 输出片段" in record.message or "原始 LLM 输出" in record.message
-            for record in error_logs
+            "LLM 输出片段" in record.message
+            for record in warning_logs
         )