turn player into primary if only one left

observers/game_observer.go

@@ -3,6 +3,8 @@ package observers
 import (
 	"openquell/components"
 
+	"log/slog"
+
 	"github.com/mlange-42/arche/ecs"
 	"github.com/mlange-42/arche/ecs/event"
 	"github.com/mlange-42/arche/generic"
@@ -27,6 +29,7 @@ func (observer *GameObserver) GetListenerCallback(comp ecs.ID) listener.Callback
 	return listener.NewCallback(
 		func(world *ecs.World, event ecs.EntityEvent) {
 			observer.RemoveEntity(event.Entity, comp)
+			slog.Debug("player removed")
 		},
 		event.EntityRemoved,
 		comp,