fix: respect configured nodeFolder in DevModeInitializer (#23293) (#23297)

Flow ignored the configured nodeFolder and always attempted to
resolve and download its own Node.js distribution.

When nodeFolder is explicitly set, Flow should rely on the Node
installation from that directory and avoid triggering the
Node download logic.

This change ensures that Node resolution correctly honors
the nodeFolder configuration in DevModeInitializer.

Fixes #23291

Co-authored-by: Haven Madray <sgpublic2002@gmail.com>

Author: vaadin-bot

vaadin-dev-server/src/main/java/com/vaadin/base/devserver/startup/DevModeInitializer.java

@@ -83,6 +83,7 @@
 import static com.vaadin.flow.server.Constants.VAADIN_SERVLET_RESOURCES;
 import static com.vaadin.flow.server.Constants.VAADIN_WEBAPP_RESOURCES;
 import static com.vaadin.flow.server.InitParameters.NODE_DOWNLOAD_ROOT;
+import static com.vaadin.flow.server.InitParameters.NODE_FOLDER;
 import static com.vaadin.flow.server.InitParameters.NODE_VERSION;
 import static com.vaadin.flow.server.InitParameters.NPM_EXCLUDE_WEB_COMPONENTS;
 import static com.vaadin.flow.server.InitParameters.REACT_ENABLE;
@@ -310,6 +311,7 @@ public static DevModeHandler initDevModeHandler(Set<Class<?>> classes,
                 .withNpmExcludeWebComponents(npmExcludeWebComponents)
                 .withNodeVersion(config.getStringProperty(NODE_VERSION,
                         DEFAULT_NODE_VERSION))
+                .withNodeFolder(config.getStringProperty(NODE_FOLDER, null))
                 .withNodeDownloadRoot(
                         URI.create(config.getStringProperty(NODE_DOWNLOAD_ROOT,
                                 NodeInstaller.DEFAULT_NODEJS_DOWNLOAD_ROOT)));