web-api-cat 0.7.20

Bindings between boa-cat (JS engine) and the DOM (html-cat tree) plus fetch (net-cat). v0.7.20 wires the `<img>` element to scripts: `src` / `alt` / `width` / `height` accessor-pair properties reflect the corresponding HTML attributes, and `naturalWidth` / `naturalHeight` / `complete` read hidden state slots populated by downstream consumers after the fetch + decode pipeline runs. Public helpers `image::set_natural_size(&img, w, h, heap)` and `image::set_complete(&img, b, heap)` let the runtime (tauri-runtime-servocat) push the decoded state back through to JS. Opens the image-rendering story for the pending Tauri opt-in backend pitch. Seventh sub-crate of a Servo-replacement webview runtime targeting Tauri.