fix(mcp): prevent internal handler serialization errors from being silently discarded or defaulting to empty strings

server/src/store.rs

@@ -28,7 +28,7 @@ impl<T: DeserializeOwned + Default + Serialize + Clone + Send + Sync + 'static>
                 let key_inner = key_clone.clone();
                 let json_data = {
                     let lock = cache_clone.read().unwrap_or_else(|e| e.into_inner());
-                    serde_json::to_vec(&*lock).ok()
+                    serde_json::to_vec(&*lock).map_err(|e| tracing::error!("Failed to serialize memory store: {}", e)).ok()
                 };
 
                 if let Some(json_data) = json_data {