fix: remove dangerous G0 X0 Y0 return-to-home rapids from Cincinnati post

Rapid traversing back to origin over a sheet of freshly cut parts risks
collisions with tipped or warped pieces. Removed from both the sheet
footer and part subprogram endings.

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

OpenNest.Posts.Cincinnati/CincinnatiPartSubprogramWriter.cs

@@ -66,7 +66,6 @@ public sealed class CincinnatiPartSubprogramWriter
             _featureWriter.Write(w, ctx);
         }
 
-        w.WriteLine("G0 X0 Y0");
         w.WriteLine($"M99 (END OF {drawingName})");
     }
 

OpenNest.Posts.Cincinnati/CincinnatiSheetWriter.cs

@@ -95,7 +95,6 @@ public sealed class CincinnatiSheetWriter
 
         // 5. Footer
         w.WriteLine("M42");
-        w.WriteLine("G0 X0 Y0");
         var emitM50 = _config.PalletExchange == PalletMode.EndOfSheet
             || (_config.PalletExchange == PalletMode.StartAndEnd && isLastSheet);
         if (emitM50)

OpenNest.Tests/Cincinnati/CincinnatiPostProcessorTests.cs

@@ -258,8 +258,7 @@ public class CincinnatiPostProcessorTests
         Assert.Contains(":200", output);
         Assert.Contains("G84", output);
 
-        // Sub-program ends with G0 X0 Y0 and M99
-        Assert.Contains("G0 X0 Y0", output);
+        // Sub-program ends with M99
         Assert.Contains("M99 (END OF Square)", output);
 
         // G92 restore after M98 call

OpenNest.Tests/Cincinnati/CincinnatiSheetWriterTests.cs

@@ -55,7 +55,6 @@ public class CincinnatiSheetWriterTests
 
         var output = sb.ToString();
         Assert.Contains("M42", output);
-        Assert.Contains("G0 X0 Y0", output);
         Assert.Contains("M50", output);
     }