Pull data from a web page. First call on a new intent prototypes the flow
via $B primitives and returns JSON. Subsequent calls on a matching intent
route to a codified browser-skill and return in ~200ms. Read-only — for
mutating flows (form fills, clicks, submissions), use /automate.
Use when asked to "scrape", "get data from", "pull", "extract from", or
"what's on" a page. (gstack)
