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/@rollup/rollup-darwin-arm64/README.md

@@ -0,0 +1,3 @@
+# `@rollup/rollup-darwin-arm64`
+
+This is the **aarch64-apple-darwin** binary for `rollup`

node_modules/@rollup/rollup-darwin-arm64/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "@rollup/rollup-darwin-arm64",
+  "version": "4.34.8",
+  "os": [
+    "darwin"
+  ],
+  "cpu": [
+    "arm64"
+  ],
+  "files": [
+    "rollup.darwin-arm64.node"
+  ],
+  "description": "Native bindings for Rollup",
+  "author": "Lukas Taegert-Atkinson",
+  "homepage": "https://rollupjs.org/",
+  "license": "MIT",
+  "repository": "rollup/rollup",
+  "main": "./rollup.darwin-arm64.node"
+}