refactor: address quality findings

crates/bat-cas-engine/src/repository.rs

@@ -46,7 +46,8 @@ impl FileSystemCasRepository {
             .await
         {
             if !existed {
-                let _ = self.storage.delete(&stored_hash).await;
+                self.delete_new_object_after_metadata_failure(&stored_hash)
+                    .await?;
             }
             return Err(error);
         }
@@ -58,13 +59,21 @@ impl FileSystemCasRepository {
             }
             Err(error) => {
                 if !existed {
-                    let _ = self.storage.delete(&stored_hash).await;
+                    self.delete_new_object_after_metadata_failure(&stored_hash)
+                        .await?;
                 }
                 Err(error)
             }
         }
     }
 
+    async fn delete_new_object_after_metadata_failure(&self, hash: &Hash) -> Result<()> {
+        match self.storage.delete(hash).await {
+            Ok(()) | Err(CasError::ObjectNotFound(_)) => Ok(()),
+            Err(error) => Err(error),
+        }
+    }
+
     /// 读取对象并验证 Hash。
     pub async fn get(&self, hash: &Hash) -> Result<Vec<u8>> {
         self.storage.get(hash).await