Fix missing state_machine import in controls.py

Resolves NameError when toggling pause (and any other control path
referencing state_machine.GameState). The module was referenced but
never imported after the recent cheat/controls edits.

engine/controls.py

@@ -8,6 +8,7 @@ from pathlib import Path
 import yaml
 
 from runtime_paths import resolve_bundle_path
+from engine import state_machine
 
 
 DEFAULT_KEYBINDINGS_PROFILE = "pc"