feat: implement streaming for large file handling

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

src/services/compression_service.rs

@@ -24,6 +24,21 @@ impl CompressionService {
         reader.read_to_end(&mut content)?;
         Ok(content)
     }
+
+    pub fn stream_item_content(
+        &self,
+        item_path: PathBuf,
+        compression: &str,
+    ) -> Result<Box<dyn Read + Send>, CoreError> {
+        let compression_type = CompressionType::from_str(compression)
+            .map_err(|e| CoreError::Compression(e.to_string()))?;
+        let engine = get_compression_engine(compression_type)
+            .map_err(|e| CoreError::Other(anyhow!(e.to_string())))?;
+
+        let reader = engine.open(item_path.clone())
+            .map_err(|e| CoreError::Other(anyhow!("Failed to open item file {:?}: {}", item_path, e)))?;
+        Ok(reader)
+    }
 }
 
 impl Default for CompressionService {