@rrweb/utils

Stopping a recording now releases the root document's mutation buffer and observer — previously the document observer was only disconnected, so each start/stop cycle leaked one buffer — and removes the cross-origin iframe message listener.

A same-origin iframe is observed once instead of re-observed on every full snapshot (checkoutEveryNth/checkoutEveryNms/manual takeFullSnapshot), so a single iframe mutation is no longer emitted once per checkout; its observers are also released when the iframe is removed or navigates away.

The untainted-MutationObserver helper iframe used on WebKit/Safari is reference-counted, so it is torn down only when the last observer stops and will get rebuilt for a later recording.