refactor(Hi.Sample): follow HiGeom's Box3d struct -- the demo displayees take ref Box3d and expand through Expanded, DemoSatellite scales its boxes with ScaledFromCenter, and MachiningProjectDisplayee forwards ref dst to the assembly

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Disp/HeidenhainCoordinateEntryDisplayee.cs

@@ -90,7 +90,7 @@ namespace Sample.Disp
             bind.ModelMatStack.Pop();
         }
         /// <inheritdoc/>
-        public void ExpandToBox3d(Box3d dst)
+        public void ExpandToBox3d(ref Box3d dst)
         {
             HardNcEnv ncEnv = NcEnv;
             if (ncEnv == null || NcEnv.CncBrand != CncBrand.Heidenhain)
@@ -107,7 +107,7 @@ namespace Sample.Disp
                 HeidenhainCycleDef247Q339, HeidenhainCycleDef7Arg, ncEnv);
 
 
-            dst.Expand(-mcXyz_AttacherAtTableMountZero + coordinateMove);
+            dst = dst.Expanded(-mcXyz_AttacherAtTableMountZero + coordinateMove);
         }
         /// <inheritdoc/>
         public Anchor GetAnchor()