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/zone.js/fesm2015/zone-patch-user-media.js

@@ -0,0 +1,23 @@
+'use strict';
+/**
+ * @license Angular v<unknown>
+ * (c) 2010-2025 Google LLC. https://angular.io/
+ * License: MIT
+ */
+function patchUserMedia(Zone) {
+    Zone.__load_patch('getUserMedia', (global, Zone, api) => {
+        function wrapFunctionArgs(func, source) {
+            return function () {
+                const args = Array.prototype.slice.call(arguments);
+                const wrappedArgs = api.bindArguments(args, func.name);
+                return func.apply(this, wrappedArgs);
+            };
+        }
+        let navigator = global['navigator'];
+        if (navigator && navigator.getUserMedia) {
+            navigator.getUserMedia = wrapFunctionArgs(navigator.getUserMedia);
+        }
+    });
+}
+
+patchUserMedia(Zone);