style: apply gdformat formatting across the entire project

Auto-format all GDScript files using gdformat from gdtoolkit.
This is a baseline formatting pass to ensure consistent style:

- Normalizes indentation and spacing
- Wraps long lines to 100 characters
- Removes trailing whitespace
- Standardizes blank lines between functions

68 files reformatted, 8 files left unchanged (3rd-party addon files
with parse errors excluded).

simulation/persistence/SaveSlotController.gd

@@ -4,6 +4,7 @@ extends Node
 
 var store := SaveSlotStore.new()
 
+
 func _unhandled_key_input(event: InputEvent) -> void:
 	if not event.pressed or event.echo:
 		return