refactor: remove multi-controller support, keep vibration fixes

Another contributor is owning multi-controller work, so this branch
drops our per-slot routing while keeping all of the Player 1 vibration
improvements (dual-motor CombinedVibration, FileObserver rumble wake,
240ms keepalive, device-vibrator refresh, intensity/mode settings,
evshim APK-copy + defensive LD_PRELOAD).

ControllerManager.java and PhysicalControllerHandler.kt are restored
wholesale from upstream/master. WinHandler.java is edited in place to
keep the vibration pipeline intact:

- MAX_PLAYERS: 4 → 1 (per-slot arrays auto-shrink to size 1;
  for-p-in-MAX_PLAYERS loops become single-iteration for slot 0)
- Dropped extraGamepadBuffers, extraControllers, and the
  getBufferForSlot / getControllerForSlot / setControllerForSlot /
  resolveControllerSlot helpers
- onGenericMotionEvent and onKeyEvent replaced with upstream's
  single-controller adoption flow (profile.getController → fallback,
  adopt only if id == "*")
- refreshControllerMappings and initializeAssignedControllers
  simplified to slot 0 only
- startRumblePoller: memPaths[] array reduced to a single gamepad.mem

BionicProgramLauncherComponent.java: pre-creates only gamepad.mem and
hardcodes EVSHIM_MAX_PLAYERS="1". evshim APK-copy and LD_PRELOAD guard
preserved.

XServerScreen.kt: removed the InputManager.InputDeviceListener that
forwarded onDeviceDisconnected to PhysicalControllerHandler (method
no longer exists upstream). The onDispose cleanup for the handler and
exit-watch jobs is preserved.

Deleted tests that exercised the removed multi-slot code:
- app/src/test/java/app/gamenative/input/MultiControllerTest.kt
- app/src/test/java/com/winlator/inputcontrols/ControllerManagerTest.kt

Verification: JDK 17 compileDebugJavaWithJavac + compileDebugKotlin
clean. testDebugUnitTest shows the same 38 pre-existing failures as
baseline (PreInstallStepsTest, SteamUtilsFileSearchTest, etc.) — zero
new regressions. Debug APK built and installed on device; full
controller input + vibration chain traced end-to-end.

Author: TideGear

app/src/main/java/app/gamenative/ui/screen/xserver/PhysicalControllerHandler.kt

@@ -408,21 +408,7 @@ fun XServerScreen(
     var gracefulExitJob: Job? by remember { mutableStateOf(null) }
 
     DisposableEffect(Unit) {
-        // Forward controller-removed events so PhysicalControllerHandler can
-        // release stale axis state and d-pad suppression for the lost device
-        // before Android potentially recycles its deviceId for a new controller.
-        val inputManager = context.getSystemService(Context.INPUT_SERVICE) as InputManager
-        val deviceListener = object : InputManager.InputDeviceListener {
-            override fun onInputDeviceAdded(deviceId: Int) = Unit
-            override fun onInputDeviceChanged(deviceId: Int) = Unit
-            override fun onInputDeviceRemoved(deviceId: Int) {
-                physicalControllerHandler?.onDeviceDisconnected(deviceId)
-            }
-        }
-        inputManager.registerInputDeviceListener(deviceListener, null)
-
         onDispose {
-            inputManager.unregisterInputDeviceListener(deviceListener)
             physicalControllerHandler?.cleanup()
             physicalControllerHandler = null
             exitWatchJob?.cancel()