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/@jsonjoy.com/fs-node-to-fsa/lib/NodePermissionStatus.d.ts

@@ -0,0 +1,8 @@
+/**
+ * @see [MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/API/PermissionStatus)
+ */
+export declare class NodePermissionStatus {
+    readonly name: string;
+    readonly state: 'granted' | 'denied' | 'prompt';
+    constructor(name: string, state: 'granted' | 'denied' | 'prompt');
+}