Cycling smart pointers when creating lambda signal-slot connection

```cpp
auto surface = _new ...;
connect(clicked, surface, [surface]() {
...
});
```

In this example, `surface` is referenced in signal-slot connection lambda, causing the surface to never destroy by itself.

The issue provides no repository files or tests; begin by locating the connect implementation and the signal-slot lambda ownership path shown in the example. Reproduce the retained-surface behavior, then verify that the connection no longer keeps the surface alive after its intended owners are gone.

Written by the indexing model from the issue text.