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/is-inside-container/readme.md

@@ -0,0 +1,36 @@
+# is-inside-container
+
+> Check if the process is running inside a container
+
+## Install
+
+```sh
+npm install is-inside-container
+```
+
+## Usage
+
+```js
+import isInsideContainer from 'is-inside-container';
+
+if (isInsideContainer()) {
+	console.log('Running inside a container');
+}
+```
+
+## CLI
+
+```sh
+is-inside-container
+```
+
+Exits with code 0 if inside a container and 2 if not.
+
+## Supported containers
+
+- Docker
+- Podman
+
+## Related
+
+- [is-docker](https://github.com/sindresorhus/is-docker) - Check if the process is running inside a Docker container