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/zone.js/fesm2015/zone-patch-canvas.js

@@ -0,0 +1,20 @@
+'use strict';
+/**
+ * @license Angular v<unknown>
+ * (c) 2010-2025 Google LLC. https://angular.io/
+ * License: MIT
+ */
+function patchCanvas(Zone) {
+    Zone.__load_patch('canvas', (global, Zone, api) => {
+        const HTMLCanvasElement = global['HTMLCanvasElement'];
+        if (typeof HTMLCanvasElement !== 'undefined' &&
+            HTMLCanvasElement.prototype &&
+            HTMLCanvasElement.prototype.toBlob) {
+            api.patchMacroTask(HTMLCanvasElement.prototype, 'toBlob', (self, args) => {
+                return { name: 'HTMLCanvasElement.toBlob', target: self, cbIdx: 0, args: args };
+            });
+        }
+    });
+}
+
+patchCanvas(Zone);