Issue 3: the New-Automation modal was taller than the screen and the whole
dialog scrolled. New <x-modal> component: header + footer are fixed (shrink-0),
only the body scrolls, capped to max-h-85dvh so the page never scrolls. Refactored
create-automation (now a responsive 2-column grid, widened to 3xl), add-device,
ring-connect and add-person onto it — the standard for every modal going forward.
Verified: modal fits a 720px viewport with no page scroll; create flow still works.
12/12 tabs clean, suite green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>