Hotfix: Crash After 1-Hour Runtime

Memory Leak / Orphan Nodes
Added explicit cleanup of spawned apple nodes and their child resources to eliminate orphaned Area2D, Sprite2D, AnimationPlayer, and AudioStreamPlayer2D instances.

Save-Thread Stability
Ensured the background save thread runs at LOW priority and joins before spawning new saves, preventing CPU contention.

Thanks for your patience!🧡🍎🍏
This should eliminate the silent crash around the 1 hour mark and keep your session running smoothly!