Support the iPhone Duo interior display in the player

The interior display refuses programmatic rotation
(UISceneErrorDomain 101: "The current windowing mode does not allow for
programmatic changes to interface orientation"), so the rotate/fullscreen
button did nothing there and the failure was swallowed.

- OrientationManager tracks `canRotateProgrammatically` (from the hinge
  state, cleared when a geometry request is refused) and is @Observable.
- The fullscreen button takes the iPad path when rotation is unavailable:
  details toggle in portrait, floating panel toggle in landscape, icon
  follows the panel state; orientation lock is hidden. The refused request
  itself falls back to the details toggle. Accelerometer-driven rotation
  requests are gated the same way.
- Corner layout gate is size-only on iOS (≥900×600 including safe areas,
  so the status bar toggling with the layout can't oscillate it); the
  layout-mode setting is exposed on foldables via a hinge presence check.
- Corner layout on iPhone always hides the status bar (the interior's
  landscape bar is a ~57pt column) and pads by the live top inset only,
  instead of the transient 82pt inset seen while unfolding.
- The player hosting controller nudges its safe area after size
  transitions so fold/unfold doesn't leave SwiftUI with stale insets.

Yattee/Views/Settings/PlayerControls/PanelSettingsView.swift

@@ -22,7 +22,8 @@ struct PanelSettingsView: View {
     @State private var commentsShowAvatars: Bool = true
     @State private var commentsPillMode: CommentsPillMode = .pill
 
-    /// Corner layout exists on iPad and macOS only.
+    /// Corner layout exists on iPad and macOS, and on a foldable iPhone whose
+    /// interior display is large enough (see `hasHinge`).
     static var supportsCornerLayout: Bool {
         #if os(macOS)
         return true
@@ -31,12 +32,17 @@ struct PanelSettingsView: View {
         #endif
     }
 
+    /// Foldable iPhone: the interior display qualifies for the corner layout.
+    @State private var hasHinge = false
+
+    private var showsLayoutSection: Bool { Self.supportsCornerLayout || hasHinge }
+
     /// iPhone has no page bar: the list configures inline sections instead.
     private var usesSections: Bool { PanelSettings.isSectionsOnlyDevice }
 
     var body: some View {
         List {
-            if Self.supportsCornerLayout {
+            if showsLayoutSection {
                 layoutSection
             }
             visibilitySection
@@ -66,6 +72,7 @@ struct PanelSettingsView: View {
         .onChange(of: viewModel.activePreset?.id) { _, _ in
             syncLocalState()
         }
+        .observeHinge(hasHinge: $hasHinge)
     }
 
     // MARK: - Layout Section