Bindings between boa-cat (JS engine) and the DOM (html-cat tree) plus fetch (net-cat). v0.6.4 adds `Element.style` as a fresh empty Object on each element, so common script patterns like `el.style.color = 'red'` and `el.style.display = 'none'` round-trip through the engine's normal property storage without throwing. Inline `style="..."` attribute parsing and back-prop into layout-cat are deferred; the goal here is script compatibility. Seventh sub-crate of a Servo-replacement webview runtime targeting Tauri.