Bindings between boa-cat (JS engine) and the DOM (html-cat tree) plus fetch (net-cat). v0.7.5 extends the v0.7.4 event system with spec-compliant event flow: `dispatchEvent` decorates the supplied event with `target` / `currentTarget` / `defaultPrevented` plus `preventDefault()` / `stopPropagation()` / `stopImmediatePropagation()` methods. Listeners interact with the dispatch as they would in a real browser without needing a `new Event()` constructor. `dispatchEvent` returns `false` when any listener called `preventDefault`. Seventh sub-crate of a Servo-replacement webview runtime targeting Tauri.