chore: sort using directives

Auto-formatter reordering of using statements across the solution.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest.Core/Timing.cs

@@ -1,8 +1,8 @@
-using System;
-using System.Linq;
-using OpenNest.CNC;
+using OpenNest.CNC;
 using OpenNest.Converters;
 using OpenNest.Geometry;
+using System;
+using System.Linq;
 
 namespace OpenNest
 {
@@ -83,7 +83,7 @@ namespace OpenNest
                     time += TimeSpan.FromSeconds(info.TravelDistance / cutParams.RapidTravelRate);
                     break;
             }
-            
+
             time += TimeSpan.FromTicks(info.PierceCount * cutParams.PierceTime.Ticks);
 
             return time;