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/http-proxy-middleware/dist/get-plugins.js

@@ -0,0 +1,13 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.getPlugins = getPlugins;
+const default_1 = require("./plugins/default");
+function getPlugins(options) {
+    // don't load default errorResponsePlugin if user has specified their own
+    const maybeErrorResponsePlugin = options.on?.error ? [] : [default_1.errorResponsePlugin];
+    const defaultPlugins = options.ejectPlugins
+        ? [] // no default plugins when ejecting
+        : [default_1.debugProxyErrorsPlugin, default_1.proxyEventsPlugin, default_1.loggerPlugin, ...maybeErrorResponsePlugin];
+    const userPlugins = options.plugins ?? [];
+    return [...defaultPlugins, ...userPlugins];
+}