Style: Harmonize header includes in modules

This applies our existing style guide, and adds a new rule to that style
guide for modular components such as platform ports and modules:

Includes from the platform port or module ("local" includes) should be listed
first in their own block using relative paths, before Godot's "core" includes
which use "absolute" (project folder relative) paths, and finally thirdparty
includes.

Includes in `#ifdef`s come after their relevant section, i.e. the overall
structure is:

- Local includes
  * Conditional local includes
- Core includes
  * Conditional core includes
- Thirdparty includes
  * Conditional thirdparty includes

2 files changed, 3 insertions, 2 deletions

diff --git a/modules/csg/csg_shape.h b/modules/csg/csg_shape.h
index d0e4d0c8cd..6ac71b6946 100644
--- a/modules/csg/csg_shape.h
+++ b/modules/csg/csg_shape.h
@@ -31,12 +31,12 @@
 #ifndef CSG_SHAPE_H
 #define CSG_SHAPE_H
 
-#define CSGJS_HEADER_ONLY
-
 #include "csg.h"
+
 #include "scene/3d/path_3d.h"
 #include "scene/3d/visual_instance_3d.h"
 #include "scene/resources/concave_polygon_shape_3d.h"
+
 #include "thirdparty/misc/mikktspace.h"
 
 class CSGShape3D : public GeometryInstance3D {
diff --git a/modules/csg/editor/csg_gizmos.h b/modules/csg/editor/csg_gizmos.h
index 89a4305683..deac1d428d 100644
--- a/modules/csg/editor/csg_gizmos.h
+++ b/modules/csg/editor/csg_gizmos.h
@@ -34,6 +34,7 @@
 #ifdef TOOLS_ENABLED
 
 #include "../csg_shape.h"
+
 #include "editor/editor_plugin.h"
 #include "editor/plugins/node_3d_editor_gizmos.h"