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/plugin_manager.py

@@ -188,7 +188,8 @@ class PluginManager:
 
         conn.execute(
             """INSERT INTO plugins
-               (id, name, plugin_type, project_id, status, config, created_at, updated_at, use_count)
+               (id, name, plugin_type, project_id, status, config, created_at, updated_at,
+                use_count)
                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)""",
             (
                 plugin.id,
@@ -1204,7 +1205,8 @@ class WebDAVSyncManager:
         conn.execute(
             """INSERT INTO webdav_syncs
                (id, name, project_id, server_url, username, password, remote_path,
-                sync_mode, sync_interval, last_sync_status, is_active, created_at, updated_at, sync_count)
+                sync_mode, sync_interval, last_sync_status, is_active, created_at, updated_at,
+                sync_count)
                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)""",
             (
                 sync_id,