lnbits-qrcode has no `options` prop — it renders width:100% of its
parent, capped by a `max-width` PROP that defaults to 450px. So the
previous `:options="{width: qrZoom.size}"` was dead: the QR only ever
grew to its container, and inside the zoom dialog's items-center flex
column the container collapsed to the QR's natural width, so "enlarge"
barely changed anything.
Wrap the zoom QR in an explicit full-width div (capped 96vw), feed the
real `max-width` prop, hide the component's own copy/download buttons
for a clean scan target, and size it to ~full shorter-viewport-edge.
Also swap the inline pair-dialog QR's dead `:options` for `max-width`.
The `min-width: 480px` on dialog cards overrode `max-width: 95vw` on
narrow viewports (CSS min-width wins on conflict), so add-machine / pair
/ etc. dialogs overflowed off-screen on phones. Switch every dialog card
from minWidth to width so maxWidth can shrink it to fit.
Also cap the tall add-machine form section at 65vh with a scroll
container so all fields stay reachable on short screens.
For pairing, the seed-URL QR is now tappable and has an "Enlarge for
scanning" button opening a fullscreen maximized QR sized to the shorter
viewport edge — maximises visibility to the spire's scan camera.
