replace react-nav header hack with scroll edge interaction module

- new expo-scroll-edge-interaction native module (iOS-only) that sets up
  UIScrollEdgeElementContainerInteraction on iOS 26+
- new ScrollEdgeInteractionProvider context and hooks
- Layout.Screen gains `transparentHeader` prop
- Layout.Header.Outer auto-detects transparent mode from context
- List auto-registers scroll view and applies content inset

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/expo-scroll-edge-interaction/src/ExpoScrollEdgeInteraction.types.ts

@@ -0,0 +1,11 @@
+import {type ViewStyle} from 'react-native'
+
+export type ScrollEdgeInteractionEdge = 'top' | 'bottom' | 'left' | 'right'
+
+export interface ExpoScrollEdgeInteractionViewProps {
+  nodeHandle: number | null
+  scrollViewTag: number | null
+  edge?: ScrollEdgeInteractionEdge
+  children: React.ReactNode
+  style?: ViewStyle
+}

modules/expo-scroll-edge-interaction/src/ExpoScrollEdgeInteractionView.ios.tsx

@@ -0,0 +1,13 @@
+import {requireNativeViewManager} from 'expo-modules-core'
+
+import {type ExpoScrollEdgeInteractionViewProps} from './ExpoScrollEdgeInteraction.types'
+
+const NativeView: React.ComponentType<ExpoScrollEdgeInteractionViewProps> =
+  requireNativeViewManager('ExpoScrollEdgeInteraction')
+
+export function ExpoScrollEdgeInteractionView({
+  children,
+  ...rest
+}: ExpoScrollEdgeInteractionViewProps) {
+  return <NativeView {...rest}>{children}</NativeView>
+}

modules/expo-scroll-edge-interaction/src/ExpoScrollEdgeInteractionView.tsx

@@ -0,0 +1,7 @@
+import {type ExpoScrollEdgeInteractionViewProps} from './ExpoScrollEdgeInteraction.types'
+
+export function ExpoScrollEdgeInteractionView({
+  children,
+}: React.PropsWithChildren<ExpoScrollEdgeInteractionViewProps>) {
+  return children
+}