fix: apply grails-bom platform to all declarable configurations

The Spring Dependency Management plugin applied version constraints
globally to every configuration via configurations.all() and
resolutionStrategy.eachDependency(). With the switch to Gradle's native
platform(), version constraints must be added explicitly.

Apply the grails-bom platform to all declarable configurations using
configureEach, matching the previous global behavior. Non-declarable
configurations (apiElements, runtimeElements, etc.) inherit constraints
through their parent configurations. Also ensure the developmentOnly
configuration always exists via maybeCreate, regardless of whether the
Spring Boot plugin has been applied.

Assisted-by: Claude Code <Claude@Claude.ai>

Author: jamesfredley

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

@@ -384,7 +384,21 @@ ${importStatements}
         String grailsVersion = (project.findProperty('grailsVersion') ?: BuildSettings.grailsVersion) as String
         String bomCoordinates = "org.apache.grails:grails-bom:${grailsVersion}" as String
 
-        project.dependencies.add('implementation', project.dependencies.platform(bomCoordinates))
+        // Ensure the developmentOnly configuration exists. Spring Boot's plugin
+        // normally creates this, but using maybeCreate guarantees it is available
+        // even if plugin ordering changes or Spring Boot is not applied.
+        project.configurations.maybeCreate('developmentOnly')
+
+        // Apply the BOM platform to all declarable configurations, matching the
+        // behavior of the Spring Dependency Management plugin which applied version
+        // constraints globally via configurations.all() + resolutionStrategy.eachDependency().
+        // Non-declarable configurations (e.g. apiElements, runtimeElements) inherit
+        // constraints through their parent configurations.
+        project.configurations.configureEach { Configuration conf ->
+            if (conf.canBeDeclared) {
+                project.dependencies.add(conf.name, project.dependencies.platform(bomCoordinates))
+            }
+        }
 
         project.afterEvaluate {
             BomManagedVersions managedVersions = BomManagedVersions.resolve(project, bomCoordinates)