feat: implement streaming for large file handling

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

src/modes/server/api/item.rs

@@ -261,8 +261,8 @@ async fn stream_item_content_response_with_metadata(
         let is_binary = if let Some(binary_val) = metadata.get("binary") {
             binary_val == "true"
         } else {
-            // If binary metadata isn't set, we need to check the content
-            match item_service.get_item_content_info(item_id).await {
+            // If binary metadata isn't set, we need to check the content using streaming approach
+            match item_service.get_item_content_info_streaming(item_id).await {
                 Ok((_, _, is_binary)) => is_binary,
                 Err(e) => {
                     warn!("Failed to get content info for binary check for item {}: {}", item_id, e);