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/Services/OrientationManager.swift

@@ -8,16 +8,41 @@
 
 #if os(iOS)
 
+import Observation
 import UIKit
 
 /// Provides supported interface orientations.
 /// Supports in-app orientation locking to the current orientation.
 @MainActor
+@Observable
 final class OrientationManager {
     static let shared = OrientationManager()
 
     private init() {}
 
+    /// Whether `requestGeometryUpdate(.iOS(interfaceOrientations:))` is honored
+    /// in the current windowing mode. False on the iPhone Duo interior display,
+    /// where the system refuses programmatic rotation (`UISceneErrorDomain` 101)
+    /// the same way it does for iPad multitasking. Set from the hinge state and
+    /// cleared when a request is refused, so the player falls back to the
+    /// iPad-style details toggle instead of doing nothing.
+    var canRotateProgrammatically = true
+
+    /// `UISceneErrorDomain` code returned when the windowing mode forbids
+    /// programmatic interface orientation changes.
+    static let orientationChangeForbiddenErrorCode = 101
+
+    /// Records a refused rotation request; returns true when the error is the
+    /// windowing-mode refusal (as opposed to a transient failure).
+    @discardableResult
+    func noteGeometryUpdateFailure(_ error: Error) -> Bool {
+        let nsError = error as NSError
+        guard nsError.domain == UISceneErrorDomain,
+              nsError.code == Self.orientationChangeForbiddenErrorCode else { return false }
+        canRotateProgrammatically = false
+        return true
+    }
+
     /// The orientation to lock to when `isLocked` is true.
     /// Updated when orientation lock is enabled to capture current orientation.
     private var lockedOrientation: UIInterfaceOrientationMask?