Pickups + Save-diff

scripts/world/PickupMarker.cs

@@ -0,0 +1,23 @@
+using Godot;
+
+public partial class PickupMarker : Area2D
+{
+	public string PickupId { get; set; } = "";
+	public string ItemId { get; set; } = "";
+
+	public override void _Ready()
+	{
+		BodyEntered += OnBodyEntered;
+	}
+
+	private void OnBodyEntered(Node2D body)
+	{
+		if (body is not CharacterBody2D) return;
+
+		// Defer to avoid freeing during signal processing edge cases
+		EmitSignal(SignalName.PickedUp, PickupId, ItemId);
+	}
+
+	[Signal]
+	public delegate void PickedUpEventHandler(string pickupId, string itemId);
+}