- el_runtime.js: add 19 dom_* builtins (browser-only, throw in Node),
window_set/window_get for exposing El functions to the browser global
scope, and native_js/native_js_call escape hatches for third-party libs
- codegen-js.el: destructure all new builtins in generated preamble; add
@async decorator support that emits async function + await at call sites
for known-async HTTP builtins and user-declared @async functions; pre-
registration pass ensures forward calls to @async functions get await
- spec/codegen-js.md: mark Phase 3 (DOM bridge) implemented, document
@async approach and its limitations, update builtin table and status
- examples/browser-counter.el: canonical example showing dom_get_element,
dom_set_text, dom_is_null, window_set, and state_set/get