Create room 006 (Cave Entrance) and wire to room 005

- Added kq4_006_cave_entrance scene with west exit to room 005
- Updated room 005 to include target UID for room 006 transition
- Room 006 south exit to room 012 omitted (room 012 doesn't exist yet)
- Both transitions validated with exit checker

scenes/kq4_006_cave_entrance/kq4_006_cave_entrance.gd

@@ -0,0 +1,5 @@
+extends Scene
+
+
+func _on_forest_grove_interacted() -> void:
+	$kq4_005_forest_grove.default_script(self)