Replace UIScreen.main with scene-local context

- List row hairlines read displayScale from the SwiftUI environment
- MPV render views take contentScaleFactor from traitCollection and
  re-apply it on UITraitDisplayScale changes
- ExpandedPlayerWindow scales against the presenting view's own height
- MPVPiPBridge sizes the PiP layer from the container view's window
  scene screen (UIScreen.main kept only as a nil-window fallback)
- WideScreenPlayerLayout falls back to the offered geometry size
- Remote control fullscreen state comes from the player sheet's layout
  pass via NavigationCoordinator.isWideScreenLayoutActive instead of
  screen bounds aspect
- Orientation TODOs for Dynamic Island side detection and
  prefersInterfaceOrientationLocked

Yattee/Views/Components/SourceListRow.swift

@@ -16,6 +16,8 @@ struct SourceListRow<Content: View>: View {
 
     @ViewBuilder let content: () -> Content
 
+    @Environment(\.displayScale) private var displayScale
+
     /// Horizontal padding for row content.
     #if os(macOS)
     private let horizontalPadding: CGFloat = 12
@@ -64,7 +66,7 @@ struct SourceListRow<Content: View>: View {
         #if os(iOS)
         Rectangle()
             .fill(Color(uiColor: .separator))
-            .frame(height: 1 / UIScreen.main.scale)
+            .frame(height: 1 / displayScale)
             .padding(.leading, dividerLeadingPadding)
         #elseif os(macOS)
         Rectangle()

Yattee/Views/Components/VideoListRow.swift

@@ -56,6 +56,8 @@ struct VideoListRow<Content: View>: View {
 
     @ViewBuilder let content: () -> Content
 
+    @Environment(\.displayScale) private var displayScale
+
     /// Horizontal padding for row content.
     private let horizontalPadding: CGFloat = 16
 
@@ -91,7 +93,7 @@ struct VideoListRow<Content: View>: View {
         #if os(iOS)
         Rectangle()
             .fill(Color(uiColor: .separator))
-            .frame(height: 1 / UIScreen.main.scale)
+            .frame(height: 1 / displayScale)
             .padding(.leading, dividerLeadingPadding)
         #elseif os(macOS)
         Rectangle()