fix: remove unused variables and content_len

Co-authored-by: aider (openai/andrew/openrouter/deepseek/deepseek-chat-v3.1) <aider@aider.chat>

src/services/async_item_service.rs

@@ -168,7 +168,7 @@ impl AsyncItemService {
         }
         
         // Get a streaming reader for the content
-        let (mut reader, content_len) = {
+        let mut reader = {
             let db = self.db.clone();
             let item_service = self.item_service.clone();
             tokio::task::spawn_blocking(move || {
@@ -184,10 +184,7 @@ impl AsyncItemService {
                     &item_with_meta.item.compression
                 )?;
                 
-                // Get content length from metadata
-                let content_len = item_with_meta.item.size.unwrap_or(0) as u64;
-                
-                Ok::<_, CoreError>((reader, content_len))
+                Ok::<_, CoreError>(reader)
             })
             .await
             .unwrap()?