fix: auto-fix code issues (cron)

- 修复重复导入/字段 (llm_client.py 中的重复注释)
- 修复PEP8格式问题 (E501行长度超过100字符)
- 修复多行SQL语句和字符串格式化
- 修复f-string过长问题

涉及文件:
- backend/developer_ecosystem_manager.py
- backend/document_processor.py
- backend/enterprise_manager.py
- backend/export_manager.py
- backend/growth_manager.py
- backend/llm_client.py
- backend/localization_manager.py
- backend/main.py
- backend/neo4j_manager.py
- backend/ops_manager.py
- backend/performance_manager.py
- backend/plugin_manager.py
- backend/search_manager.py
- backend/security_manager.py
- backend/subscription_manager.py
- backend/tenant_manager.py
- backend/test_phase8_task6.py
- backend/test_phase8_task8.py
- backend/tingwu_client.py
- backend/workflow_manager.py

backend/performance_manager.py

@@ -496,7 +496,8 @@ class CacheManager:
         # 预热实体数据
         entities = conn.execute(
             """SELECT e.*,
-                      (SELECT COUNT(*) FROM entity_mentions m WHERE m.entity_id = e.id) as mention_count
+                      (SELECT COUNT(*) FROM entity_mentions m WHERE m.entity_id = e.id)
+                      as mention_count
                FROM entities e
                WHERE e.project_id = ?
                ORDER BY mention_count DESC
@@ -788,7 +789,8 @@ class DatabaseSharding:
                 target_conn.execute(
                     """
                     INSERT OR REPLACE INTO entity_relations
-                    (id, project_id, source_entity_id, target_entity_id, relation_type, evidence, created_at)
+                    (id, project_id, source_entity_id, target_entity_id, relation_type,
+                     evidence, created_at)
                     VALUES (?, ?, ?, ?, ?, ?, ?)
                 """,
                     tuple(relation),
@@ -1409,7 +1411,10 @@ class PerformanceMonitor:
             "type": "performance_alert",
             "metric": metric.to_dict(),
             "threshold": self.alert_threshold,
-            "message": f"{metric.metric_type} exceeded threshold: {metric.duration_ms}ms > {self.alert_threshold}ms",
+            "message": (
+                f"{metric.metric_type} exceeded threshold: "
+                f"{metric.duration_ms}ms > {self.alert_threshold}ms"
+            ),
         }
 
         for handler in self.alert_handlers: