Park the Beta pointer instead of freezing it when there's nothing to solve

StateManager holds the last value written, so 'write nothing' reads as 'keep
pointing there forever'. If the pointer got switched off, or its calibration was
dropped by a presentation change, ingest simply stopped writing IR axes and the
game's cursor stayed pegged wherever it last landed. Now it writes centre + hide
once and remembers it did.

Done on the CoreMotion queue rather than from the setter that turned the pointer
off, because ciface::iOS::StateManager has no internal locking at all -- plain
std::map writes, see StateManager.cpp -- so every Beta pointer write is kept on
that one serial queue rather than adding a second writing thread. (The stock app
already races StateManager between the main thread and TCDeviceMotion's queue;
that's pre-existing and not something this branch should make worse.)

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: bward-dev1

Source/iOS/App/Common/Controller/VirtualWiiRemote.swift

@@ -57,6 +57,10 @@ import UIKit
   private let hideStateLock = NSLock()
   private var lastHidden = false
 
+  /// Whether a pointer position has been written since the last time it was parked. Touched only
+  /// from the CoreMotion delivery queue, which is serial, so it needs no lock.
+  private var wrotePointer = false
+
   /// ciface::iOS::InputBackend::PopulateDevices registers eight Touchscreen devices: 0-3 are
   /// GameCube pads, 4-7 are Wii Remotes. So slots 1-4 are ports 4-7.
   @objc public init(slot: Int, presentation: WiiRemotePresentation) {
@@ -255,6 +259,7 @@ import UIKit
   /// horizontal one is not. This is the same trick TCWiiPad already uses when it writes
   /// `[y, y, x, x]` starting at wiiInfrared + 1 -- there, y arrives in UIKit's y-down space, so
   /// no negation is needed and none appears.
+  ///
   /// `overshoot` is PointerSolution.overshoot: 0 at the centre, 1 at an edge, more beyond.
   @objc public func submitPointer(x: Double, y: Double, overshoot: Double) {
     let horizontal = Float(x)
@@ -322,7 +327,23 @@ import UIKit
     submitIMU(motion, orientation: motionOrientation(for: snapshot))
 
     if let solution = solution {
+      wrotePointer = true
+
       submitPointer(x: solution.x, y: solution.y, overshoot: solution.overshoot)
+    } else if wrotePointer {
+      // Nothing to solve any more -- the pointer was switched off, or the calibration was dropped
+      // by a presentation change. Just stopping would leave the IR axes pegged wherever they last
+      // landed, and the game's cursor stuck there: StateManager holds the last value written, so
+      // "write nothing" reads as "keep pointing there forever". Park it at the centre and hide it
+      // once instead.
+      //
+      // Done here, on the motion queue, rather than from the setter that turned the pointer off.
+      // ciface::iOS::StateManager has no internal locking at all (see StateManager.cpp -- plain
+      // std::map writes), so every Beta pointer write is kept on this one queue rather than adding
+      // a second writing thread.
+      wrotePointer = false
+
+      submitPointer(x: 0, y: 0, overshoot: .infinity)
     }
   }