fix(core): reset error baseline after filtering YooAsset catalog errors

BuildManager was incorrectly detecting false positive errors during
step 4/4 (GeneratePolymorphicCodes) because the error count baseline
was not reset after step 3/4 filtered out known YooAsset catalog errors.

The YooAsset PreprocessBuildCatalog throws "Object reference not set"
when CatalogTools.CreateCatalogFile is called with null decryption
services during HybridCLR's GenerateAll step. This error is correctly
filtered by CheckForErrorsExcluding, but subsequent steps still saw
the elevated error count.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: JasonXuDeveloper - 傑 <jason@xgamedev.net>

Author: JasonXuDeveloper

UnityProject/Packages/com.jasonxudeveloper.jengine.core/Editor/CustomEditor/BuildManager.cs

@@ -237,6 +237,10 @@ private void ExecuteCurrentStep()
                     CheckForErrorsExcluding("Step 3/4 failed - HybridCLR generation failed",
                         "Create package main catalog file failed");
 
+                    // Reset error baseline after filtering excluded errors
+                    // so subsequent steps don't see the ignored YooAsset catalog errors
+                    _errorCountAtStart = GetUnityErrorCount();
+
                     _currentStep = BuildStep.GeneratePolymorphicCodes;
                     break;