Fix Shake Detector not working when app in background (#40)

* feat: update shake detection settings to reduce cooldown and feedback options

* fix: shake detector not detecting in background

* enhance shake action handling to avoid unnecessary feedback

* disable shake detector when player not playing anything

* refactor: remove outdated TODO regarding shake detection optimization

* refactor: comment out notifyListeners call in restartTimer method for clarity

lib/features/sleep_timer/core/sleep_timer.dart

@@ -28,6 +28,9 @@ class SleepTimer {
   /// The timer that will pause the player
   Timer? timer;
 
+  /// is the sleep timer actively counting down
+  bool get isActive => timer != null && timer!.isActive;
+
   /// for internal use only
   /// when the timer was started
   DateTime? startedAt;

lib/features/sleep_timer/providers/sleep_timer_provider.dart

@@ -54,7 +54,7 @@ class SleepTimer extends _$SleepTimer {
   void restartTimer() {
     state?.restartTimer();
 
-    ref.notifyListeners();
+    // ref.notifyListeners(); // see https://github.com/Dr-Blank/Vaani/pull/40 for more information on why this is commented out
   }
 
   void cancelTimer() {

lib/features/sleep_timer/providers/sleep_timer_provider.g.dart

@@ -6,7 +6,7 @@ part of 'sleep_timer_provider.dart';
 // RiverpodGenerator
 // **************************************************************************
 
-String _$sleepTimerHash() => r'9d9f20267da91e5483151b58b7d4d7c0762c3ca7';
+String _$sleepTimerHash() => r'4f80bcc342e918c70c547b8b24790ccd88aba8c3';
 
 /// See also [SleepTimer].
 @ProviderFor(SleepTimer)