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/entity_aligner.py

@@ -178,7 +178,7 @@ class EntityAligner:
         return best_match
 
     def _fallback_similarity_match(
-        self, entities: list[object], name: str, exclude_id: str | None = None
+        self, entities: list[object], name: str, exclude_id: str | None = None,
     ) -> object | None:
         """
         回退到简单的相似度匹配（不使用 embedding）
@@ -212,7 +212,7 @@ class EntityAligner:
         return None
 
     def batch_align_entities(
-        self, project_id: str, new_entities: list[dict], threshold: float | None = None
+        self, project_id: str, new_entities: list[dict], threshold: float | None = None,
     ) -> list[dict]:
         """
         批量对齐实体
@@ -232,7 +232,7 @@ class EntityAligner:
 
         for new_ent in new_entities:
             matched = self.find_similar_entity(
-                project_id, new_ent["name"], new_ent.get("definition", ""), threshold=threshold
+                project_id, new_ent["name"], new_ent.get("definition", ""), threshold=threshold,
             )
 
             result = {