fix: auto-fix code issues (cron)

- 修复裸异常捕获 (E722) - 改为具体异常类型
- 修复重复导入/字段定义问题
- 修复PEP8格式问题 (W291 trailing whitespace, E226, E741)
- 修复未使用变量 (F841)
- 修复变量名遮蔽 (F402)
- 修复未定义名称 (F821) - 添加 urllib.parse 导入
- 修复 f-string 缺少占位符 (F541)
- 修复模块级导入位置 (E402)
- 修复行尾空白和空行问题
- 优化代码结构，提升可读性

backend/main.py

@@ -6,7 +6,6 @@ Knowledge Growth: Multi-file fusion + Entity Alignment + Document Import
 ASR: 阿里云听悟 + OSS
 """
 
-from fastapi.responses import StreamingResponse
 import os
 import sys
 import json
@@ -14,14 +13,15 @@ import httpx
 import uuid
 import io
 import time
+import logging
+from datetime import datetime, timedelta
+from typing import List, Optional, Union, Dict, Any
+
 from fastapi import FastAPI, File, UploadFile, HTTPException, Form, Depends, Header, Request, Query, Body
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.staticfiles import StaticFiles
-from fastapi.responses import JSONResponse
+from fastapi.responses import JSONResponse, StreamingResponse
 from pydantic import BaseModel, Field
-from typing import List, Optional, Union, Dict, Any
-from datetime import datetime, timedelta
-import logging
 
 # Configure logger
 logger = logging.getLogger(__name__)
@@ -9269,7 +9269,7 @@ async def list_tenant_permissions_endpoint(_=Depends(verify_api_key)):
     """获取所有可用的租户权限列表"""
     if not TENANT_MANAGER_AVAILABLE:
         raise HTTPException(status_code=500, detail="Tenant manager not available")
-    
+
     tenant_manager = get_tenant_manager()
     return {
         "permissions": [
@@ -11082,17 +11082,17 @@ async def list_languages(
     return {
         "languages": [
             {
-                "code": l.code,
-                "name": l.name,
-                "name_local": l.name_local,
-                "is_rtl": l.is_rtl,
-                "is_active": l.is_active,
-                "is_default": l.is_default,
-                "date_format": l.date_format,
-                "time_format": l.time_format,
-                "calendar_type": l.calendar_type
+                "code": lang.code,
+                "name": lang.name,
+                "name_local": lang.name_local,
+                "is_rtl": lang.is_rtl,
+                "is_active": lang.is_active,
+                "is_default": lang.is_default,
+                "date_format": lang.date_format,
+                "time_format": lang.time_format,
+                "calendar_type": lang.calendar_type
             }
-            for l in languages
+            for lang in languages
         ],
         "total": len(languages)
     }
@@ -13088,7 +13088,8 @@ async def check_team_incentive_eligibility(
 try:
     from developer_ecosystem_manager import (
         DeveloperEcosystemManager, SDKLanguage,
-        SDKStatus, TemplateCategory, TemplateStatus, DeveloperStatus
+        SDKStatus, TemplateCategory, TemplateStatus, DeveloperStatus,
+        PluginCategory
     )
     DEVELOPER_ECOSYSTEM_AVAILABLE = True
 except ImportError as e: