The VirtualList component virtualizes large lists by rendering only visible rows plus a buffer. It is useful for long, dynamic-height datasets where rendering every row at once would be expensive.
## Component Structure
```rust
VirtualList {
// Total number of items.
count: 2000usize,
// Render buffer (approximate row count) above and below viewport.
buffer: 8usize,
// Row renderer callback receives the absolute index.
render_item: move |idx: usize| rsx! {
article { key: "{idx}", "{rows[idx].title}" }
},
}
```