feat(grails-gradle): move indy configuration from generated apps to Gradle plugin

Move the Groovy invokedynamic (indy) configuration from generated
build.gradle files to the Grails Gradle Plugin, centralizing the
setting and providing user feedback.

Changes:
- Add 'indy' property to GrailsExtension (default: false)
- Configure GroovyCompile tasks in GrailsGradlePlugin to use the
  extension's indy setting
- Display lifecycle message explaining indy is disabled for
  performance and how to enable it
- Remove hardcoded indy=false from grails-forge template
- Remove hardcoded indy=false from grails-profiles base skeleton

The message appears once per project during configuration:
  Grails: Groovy invokedynamic (indy) is disabled to improve
          performance (see issue #15293).
          To enable invokedynamic: grails { indy = true } in build.gradle

Closes #15321

Author: jamesfredley

grails-forge/grails-forge-core/src/main/java/org/grails/forge/feature/build/gradle/templates/buildGradle.rocker.raw

@@ -142,7 +142,3 @@ assets {
 
 }
 
-// https://github.com/apache/grails-core/issues/15321
-tasks.withType(GroovyCompile).configureEach {
-    groovyOptions.optimizationOptions.indy = false
-}

grails-gradle/plugins/src/main/groovy/org/grails/gradle/plugin/core/GrailsExtension.groovy

@@ -76,6 +76,14 @@ class GrailsExtension {
      */
     boolean micronautAutoSetup = true
 
+    /**
+     * Whether to enable Groovy's invokedynamic (indy) bytecode instruction for dynamic Groovy method dispatch.
+     * Disabled by default to improve performance (see GitHub issue #15293).
+     * When enabled, Groovy uses JVM invokedynamic instead of traditional callsite caching.
+     * To enable invokedynamic in build.gradle: grails { indy = true }
+     */
+    boolean indy = false
+
     DependencyHandler getPlugins() {
         if (pluginDefiner == null) {
             pluginDefiner = new PluginDefiner(project)

grails-gradle/plugins/src/main/groovy/org/grails/gradle/plugin/core/GrailsGradlePlugin.groovy

@@ -184,9 +184,14 @@ class GrailsGradlePlugin extends GroovyPlugin {
     private void configureGroovyCompiler(Project project) {
         Provider<RegularFile> groovyCompilerConfigFile = project.layout.buildDirectory.file('grailsGroovyCompilerConfig.groovy')
 
+        GrailsExtension grailsExtension = project.extensions.findByType(GrailsExtension)
+
         project.tasks.withType(GroovyCompile).configureEach { GroovyCompile c ->
             c.outputs.file(groovyCompilerConfigFile)
 
+            // Configure indy option from GrailsExtension
+            c.groovyOptions.optimizationOptions.indy = grailsExtension?.indy ?: false
+
             Closure<String> userScriptGenerator = getGroovyCompilerScript(c, project)
             c.doFirst {
                 // This isn't ideal - we're performing configuration at execution time, but the alternative would be having
@@ -216,6 +221,14 @@ class GrailsGradlePlugin extends GroovyPlugin {
                 c.groovyOptions.configurationScript = combinedFile
             }
         }
+
+        // Log indy status once per project after evaluation
+        project.afterEvaluate {
+            if (!grailsExtension?.indy) {
+                project.logger.lifecycle("Grails: Groovy invokedynamic (indy) is disabled to improve performance (see issue #15293).")
+                project.logger.lifecycle("        To enable invokedynamic: grails { indy = true } in build.gradle")
+            }
+        }
     }
 
     protected Closure<String> getGroovyCompilerScript(GroovyCompile compile, Project project) {

grails-profiles/base/skeleton/build.gradle

@@ -27,7 +27,3 @@ tasks.withType(Test).configureEach {
     useJUnitPlatform()
 }
 
-// https://github.com/apache/grails-core/issues/15321
-tasks.withType(GroovyCompile).configureEach {
-    groovyOptions.optimizationOptions.indy = false
-}