idlewatcher: refactor and fix data race

internal/utils/atomic/bool.go

@@ -0,0 +1,5 @@
+package atomic
+
+import "sync/atomic"
+
+type Bool = atomic.Bool

internal/utils/atomic/value.go

@@ -22,11 +22,11 @@ func (a *Value[T]) Store(v T) {
 }
 
 func (a *Value[T]) Swap(v T) T {
-	return a.Value.Swap(v).(T)
-}
-
-func (a *Value[T]) CompareAndSwap(oldV, newV T) bool {
-	return a.Value.CompareAndSwap(oldV, newV)
+	if v := a.Value.Swap(v); v != nil {
+		return v.(T)
+	}
+	var zero T
+	return zero
 }
 
 func (a *Value[T]) MarshalJSON() ([]byte, error) {