feat: implement streaming for large file handling

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

src/services/item_service.rs

@@ -85,6 +85,46 @@ impl ItemService {
         Ok((item_with_content.content, mime_type, is_binary))
     }
 
+    pub fn get_item_content_info_streaming(
+        &self,
+        conn: &Connection,
+        id: i64,
+    ) -> Result<(Box<dyn Read + Send>, String, bool), CoreError> {
+        let item_with_meta = self.get_item(conn, id)?;
+        let item_id = item_with_meta.item.id.ok_or_else(|| CoreError::InvalidInput("Item missing ID".to_string()))?;
+
+        if item_id <= 0 {
+            return Err(CoreError::InvalidInput(format!("Invalid item ID: {}", item_id)));
+        }
+
+        let mut item_path = self.data_path.clone();
+        item_path.push(item_id.to_string());
+        
+        let reader = self.compression_service.stream_item_content(item_path, &item_with_meta.item.compression)?;
+        
+        let metadata = item_with_meta.meta_as_map();
+        let mime_type = metadata
+            .get("mime_type")
+            .map(|s| s.to_string())
+            .unwrap_or_else(|| "application/octet-stream".to_string());
+        
+        // Check if content is binary using only the first 8192 bytes
+        let is_binary = if let Some(binary_val) = metadata.get("binary") {
+            binary_val == "true"
+        } else {
+            // Read only the first 8192 bytes for binary detection
+            let mut sample_reader = self.compression_service.stream_item_content(
+                item_path.clone(), 
+                &item_with_meta.item.compression
+            )?;
+            let mut sample_buffer = vec![0; 8192];
+            let bytes_read = sample_reader.read(&mut sample_buffer)?;
+            crate::common::is_binary::is_binary(&sample_buffer[..bytes_read])
+        };
+        
+        Ok((reader, mime_type, is_binary))
+    }
+
     pub fn find_item(&self, conn: &Connection, ids: &[i64], tags: &[String], meta: &HashMap<String, String>) -> Result<ItemWithMeta, CoreError> {
         debug!("ITEM_SERVICE: Finding item with ids: {:?}, tags: {:?}, meta: {:?}", ids, tags, meta);
         let item_maybe = match (ids.is_empty(), tags.is_empty() && meta.is_empty()) {