docs: update room navigator skill with correct get_current_room_name method

Replace raw eval JSON with godot_game_call_method for checking current room,
matching the actual Godot MCP tool interface used in practice.

.opencode/skills/kq4-room-navigator/SKILL.md

@@ -35,8 +35,9 @@ Room identification at runtime:
 
 The canonical way is via `MainGame.get_current_room_name()`:
 
+Use `godot_game_call_method` to call it directly on the node path:
 ```json
-{"command": "eval", "params": {"code": "get_tree().root.get_node('Node2D').get_current_room_name()"}}
+Call method get_current_room_name on /root/Node2D
 ```
 
 Returns a string like `"kq4_010_forest_path"`. The implementation extracts the filename from the scene script's resource path (`script_path.trim_suffix(".gd").get_file()`), NOT the node name (which is always `"background"`).