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-fsa/lib/index.d.ts

@@ -0,0 +1,33 @@
+import { CoreFileSystemDirectoryHandle } from './CoreFileSystemDirectoryHandle';
+import { CoreFsaContext, IFileSystemObserverConstructable } from './types';
+import { Superblock } from '@jsonjoy.com/fs-core';
+export * from './types';
+export * from './CoreFileSystemHandle';
+export * from './CoreFileSystemDirectoryHandle';
+export * from './CoreFileSystemFileHandle';
+export * from './CoreFileSystemSyncAccessHandle';
+export * from './CoreFileSystemWritableFileStream';
+export * from './CoreFileSystemObserver';
+export * from './CorePermissionStatus';
+export * from './FileLockManager';
+/**
+ * Create a new instance of an in-memory File System Access API
+ * implementation rooted at the root directory of the filesystem.
+ *
+ * @param ctx Optional context for the File System Access API.
+ * @param core Optional low-level file system implementation to
+ *     back the File System Access API. If not provided, a new empty
+ *     Superblock instance will be created.
+ * @param dirPath Optional path within the filesystem to use as the root
+ *     directory of the File System Access API. Defaults to `/`.
+ * @returns A File System Access API implementation `dir` rooted at
+ *     the root directory of the filesystem, as well as the `core`,
+ *     a low-level file system implementation itself. Also, returns
+ *     `FileSystemObserver`, a class that can be used to create
+ *     observers that watch for changes to files and directories.
+ */
+export declare const fsa: (ctx?: Partial<CoreFsaContext>, core?: Superblock, dirPath?: string) => {
+    core: Superblock;
+    dir: CoreFileSystemDirectoryHandle;
+    FileSystemObserver: IFileSystemObserverConstructable;
+};