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/strip-ansi/index.js

@@ -0,0 +1,14 @@
+import ansiRegex from 'ansi-regex';
+
+const regex = ansiRegex();
+
+export default function stripAnsi(string) {
+	if (typeof string !== 'string') {
+		throw new TypeError(`Expected a \`string\`, got \`${typeof string}\``);
+	}
+
+	// Even though the regex is global, we don't need to reset the `.lastIndex`
+	// because unlike `.exec()` and `.test()`, `.replace()` does it automatically
+	// and doing it manually has a performance penalty.
+	return string.replace(regex, '');
+}