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/@babel/runtime/helpers/objectWithoutPropertiesLoose.js

@@ -0,0 +1,10 @@
+function _objectWithoutPropertiesLoose(r, e) {
+  if (null == r) return {};
+  var t = {};
+  for (var n in r) if ({}.hasOwnProperty.call(r, n)) {
+    if (-1 !== e.indexOf(n)) continue;
+    t[n] = r[n];
+  }
+  return t;
+}
+module.exports = _objectWithoutPropertiesLoose, module.exports.__esModule = true, module.exports["default"] = module.exports;