Initial commit: notification-elements-demo app

Interactive Angular 19 demo for @sda/notification-elements-ui with
6 sections: Bell & Feed, Notification Center, Inbox, Comments &
Threads, Mention Input, and Full-Featured layout. Includes mock
data, dark mode toggle, and real-time event log.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

node_modules/less/test/plugins/filemanager/index.js

@@ -0,0 +1,19 @@
+(function(exports) {
+    var plugin = function(less) {
+        var FileManager = less.FileManager, TestFileManager = new FileManager();
+        function TestFileManager() { }
+        TestFileManager.loadFile = function (filename, currentDirectory, options, environment, callback) {
+            if (filename.match(/.*\.test$/)) {
+                return less.environment.fileManagers[0].loadFile('colors.test', currentDirectory, options, environment, callback);
+            }
+            return less.environment.fileManagers[0].loadFile(filename, currentDirectory, options, environment, callback);
+        };
+
+        return TestFileManager;
+    };
+
+    exports.install = function(less, pluginManager) {
+        less.environment.addFileManager(new plugin(less));
+    };
+
+})(typeof exports === 'undefined' ? this['AddFilePlugin'] = {} : exports);