Restore doLast block for htmlhelp task

Fix accidental removal during refactoring. This block moves .chm files
  from htmlhelp/ subdirectory to output root and cleans up."

Author: Jeremy Jeanne

build.gradle

@@ -8,7 +8,7 @@ buildscript {
 }
 
 plugins {
-    id 'io.github.jyjeanne.dita-ot-gradle' version '2.8.1'
+    id 'io.github.jyjeanne.dita-ot-gradle' version '2.8.2'
     // Removed: 'com.github.eerohele.saxon-gradle' - not Configuration Cache compatible
     // Replaced with: inline XsltTransformTask class below
 }
@@ -236,6 +236,20 @@ task htmlhelp(type: DitaOtTask, dependsOn: autoGenerate) {
     ditaProperties.put('args.csspath', 'css')
     ditaProperties.put('args.cssroot', "${projectDirPath}/resources/")
     ditaProperties.put('args.gen.task.lbl', 'YES')
+
+    doLast {
+        // Move .chm files using modern Gradle file operations
+        def htmlhelpDir = file("${outputDir}/htmlhelp")
+        if (htmlhelpDir.exists()) {
+            copy {
+                from htmlhelpDir
+                into outputDir
+                include '*.chm'
+            }
+            // Clean up the htmlhelp directory
+            delete htmlhelpDir
+        }
+    }
 }
 
 task cleanOutput(type: Delete) {