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/uuid/dist/esm-node/version.js

@@ -0,0 +1,11 @@
+import validate from './validate.js';
+
+function version(uuid) {
+  if (!validate(uuid)) {
+    throw TypeError('Invalid UUID');
+  }
+
+  return parseInt(uuid.substr(14, 1), 16);
+}
+
+export default version;