add app/design path

src/main/java/com/magento/idea/magento2plugin/magento/packages/Package.java

@@ -8,6 +8,7 @@
 public class Package { //NOPMD
     public static final String V_FILE_SEPARATOR = "/";
     public static String packagesRoot = "app/code";
+    public static String packagesDesignRoot = "app/design";
     public static String libWebRoot = "lib/web";
     public static String frameworkRootComposer = "vendor/magento/framework";
     public static String frameworkRootGit = "lib/internal/Magento/Framework";

src/main/java/com/magento/idea/magento2plugin/util/magento/IsFileInEditableModuleUtil.java

@@ -39,10 +39,12 @@ public static boolean execute(final Project project, final VirtualFile virtualFi
         final Settings settings = Settings.getInstance(project);
         List<String> magentoToFolders = settings.getMagentoFolders();
         final String magentoPathUrl = MagentoPathUrlUtil.execute(project);
+        final String magentoDesignUrl = MagentoPathUrlUtil.getDesignPath(project);
         if (magentoPathUrl != null) {
             if (magentoToFolders == null) {
                 magentoToFolders = List.of(
-                        magentoPathUrl
+                        magentoPathUrl,
+                        magentoDesignUrl
                 );
             } else {
                 magentoToFolders.add(

src/main/java/com/magento/idea/magento2plugin/util/magento/MagentoPathUrlUtil.java

@@ -31,4 +31,24 @@ public static String execute(Project project) {
 
         return null;
     }
+
+    /**
+     * Constructs a file URL for the Magento packages root, based on the project settings.
+     *
+     * @param project the project instance
+     * @return the constructed file URL
+     */
+    public static String getDesignPath(Project project) {
+        String magentoPath = Settings.getMagentoPath(project);
+        if (magentoPath != null) {
+            return  VirtualFileManager.constructUrl(
+                    "file",
+                    magentoPath
+                            + File.separator
+                            + Package.packagesDesignRoot
+            );
+        }
+
+        return null;
+    }
 }