Requests made by page JS (fetch/XHR/dynamic script and stylesheet loads)
run in the V8 op layer and never produced a NetworkEvent, so CDP emitted
Network.requestWillBeSent / responseReceived only for the static
navigation subresources. Puppeteer/Playwright page.on('request') and
on('response') therefore missed every XHR/JSON response, which breaks
response capture (and is the root cause of the Aviasales half of #394).
op_fetch_url now records a JsNetworkEvent keyed by the same fetch-{N} id
under which it already stores the response body. The Page drains these
into its network_events before the CDP layer emits, so they flow through
emit_navigation_events as requestWillBeSent / responseReceived /
loadingFinished alongside the document subresources, and
Network.getResponseBody resolves for them via the shared id. Applied to
both navigation paths (server process_navigation and in-process
do_navigate). The queue is capped at 4096 events per page.
Closes#406.