`preview.open` now carries the configured default viewport and `createTab`
carries the zoom/appearance defaults, so the call-shape assertions had to move
with them.

PreviewView's test stubs `browserDefaults` directly rather than deepening the
`state/session` mock: the component now reaches `useSettings`, which pulls in
`state/server`, and a test about browser chrome shouldn't drag the settings and
connection graph along with it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>