Newsroom: cron + windowed aggregate + derived + webhook

Four realtime primitives in one page. A 1Hz live.cron firehose feeds a windowed live.aggregate with three trending slices. A live.derived stats strip tracks story / view counts. The Publish form below routes through live.webhook: the server signs a payload, the page POSTs it to /api/demos/news/webhook, the framework verifies the signature and publishes a story event to every subscriber.