Add @MainActor to View, ViewModifier, Renderable, App, Scene protocols and all builders (ViewBuilder, SceneBuilder, ChildInfoProvider). Update renderToBuffer(), makeChildInfo(), resolveChildInfos() for main-actor isolation. Mark generic Equatable conformances with @preconcurrency. Update all 45 test suites with @MainActor annotation.
Centralized NotificationService with .notificationHost() modifier for
rendering stacked, auto-dismissing notifications in the top-right corner.
Notifications use a single style with theme border colors — severity
differentiation belongs to Alerts, not notifications.
- NotificationService with static accessor and environment key
- NotificationHostModifier with fade-in/out animation and vertical stacking
- NotificationTiming for opacity interpolation and word-wrap
- Box(lines:) convenience init with BufferView for pre-styled content
- LifecycleManager.resetAppearance(token:) for re-triggering animations
- 17 tests covering service, timing, word-wrap, and rendering
phranck