fix: auto-fix code issues (cron)

- 修复重复导入/字段
- 修复异常处理
- 修复PEP8格式问题
- 添加类型注解

backend/collaboration_manager.py

@@ -195,7 +195,7 @@ class CollaborationManager:
         data = f"{project_id}:{datetime.now().timestamp()}:{uuid.uuid4()}"
         return hashlib.sha256(data.encode()).hexdigest()[:32]
 
-    def _save_share_to_db(self, share: ProjectShare):
+    def _save_share_to_db(self, share: ProjectShare) -> None:
         """保存分享记录到数据库"""
         cursor = self.db.conn.cursor()
         cursor.execute(
@@ -286,7 +286,7 @@ class CollaborationManager:
             allow_export=bool(row[12]),
         )
 
-    def increment_share_usage(self, token: str):
+    def increment_share_usage(self, token: str) -> None:
         """增加分享链接使用次数"""
         share = self._shares_cache.get(token)
         if share:
@@ -403,7 +403,7 @@ class CollaborationManager:
 
         return comment
 
-    def _save_comment_to_db(self, comment: Comment):
+    def _save_comment_to_db(self, comment: Comment) -> None:
         """保存评论到数据库"""
         cursor = self.db.conn.cursor()
         cursor.execute(
@@ -616,7 +616,7 @@ class CollaborationManager:
 
         return record
 
-    def _save_change_to_db(self, record: ChangeRecord):
+    def _save_change_to_db(self, record: ChangeRecord) -> None:
         """保存变更记录到数据库"""
         cursor = self.db.conn.cursor()
         cursor.execute(
@@ -862,7 +862,7 @@ class CollaborationManager:
         }
         return permissions_map.get(role, ["read"])
 
-    def _save_member_to_db(self, member: TeamMember):
+    def _save_member_to_db(self, member: TeamMember) -> None:
         """保存成员到数据库"""
         cursor = self.db.conn.cursor()
         cursor.execute(
@@ -970,7 +970,7 @@ class CollaborationManager:
         permissions = json.loads(row[0]) if row[0] else []
         return permission in permissions or "admin" in permissions
 
-    def update_last_active(self, project_id: str, user_id: str):
+    def update_last_active(self, project_id: str, user_id: str) -> None:
         """更新用户最后活跃时间"""
         if not self.db:
             return
@@ -992,7 +992,7 @@ class CollaborationManager:
 _collaboration_manager = None
 
 
-def get_collaboration_manager(db_manager=None):
+def get_collaboration_manager(db_manager=None) -> None:
     """获取协作管理器单例"""
     global _collaboration_manager
     if _collaboration_manager is None: