A <webview> guest that attaches while the app window is hidden or minimized
never paints, and one parked off-screen stops painting, so agent snapshots
waited on a frame that never came. Agent-opened tabs now live in a
never-shown window of their own, which paints in every window state; the
panel streams them like any other server tab.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>