Ajout de la cinématique de début et refonte du système audio

Et toujours un peu de correction de bug par ci par là

entities/player/scripts/player.gd

@@ -126,26 +126,31 @@ func try_move(move_to : Vector2):
 func pick_item(item : Item) -> Item:
     AudioManager.play_sfx("PickUp")
     if data.inventory.is_full():
-        drop_item()
+        await drop_item()
+
+    var current_item : Item = null
 
     var available_slot_ind = data.inventory.get_best_available_slot_ind()
     if (
         available_slot_ind == data.inventory.current_item_ind 
         && data.inventory.items[available_slot_ind] != null
     ):
-        var current_item : Item = data.inventory.get_item()
+        current_item = data.inventory.get_item()
         data.inventory.set_item(item, available_slot_ind)
-        return current_item
     else :
         if data.inventory.set_item(item, available_slot_ind):
             data.inventory.set_current_item(available_slot_ind);
-        return null
+    
+    # Save after a timer to let the time to the item to disappear
+    get_tree().create_timer(0.1).timeout.connect(region.save)
+    return current_item
 
 func drop_item():
     var item_to_drop = data.inventory.pop_item()
     if item_to_drop:
         terrain.drop_item(item_to_drop, global_position)
         AudioManager.play_sfx("Drop")
+        region.save()
 
 func delete_item(item: Item):
     data.inventory.remove_item(item)
@@ -182,7 +187,7 @@ func use_item(item : Item):
             data.energy -= item.energy_usage
             if item.is_one_time_use():
                 data.inventory.remove_item(item)
-    region.save()
+        get_tree().create_timer(0.1).timeout.connect(region.save)
 
 func upgrade_max_energy(amount = 1):
     data.max_energy += amount