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/minipass-sized/README.md

@@ -0,0 +1,28 @@
+# minipass-sized
+
+A Minipass stream that raises an error if you get a different number of
+bytes than expected.
+
+## USAGE
+
+Use just like any old [minipass](http://npm.im/minipass) stream, but
+provide a `size` option to the constructor.
+
+The `size` option must be a positive integer, smaller than
+`Number.MAX_SAFE_INTEGER`.
+
+```js
+const MinipassSized = require('minipass-sized')
+// figure out how much data you expect to get
+const expectedSize = +headers['content-length']
+const stream = new MinipassSized({ size: expectedSize })
+stream.on('error', er => {
+  // if it's the wrong size, then this will raise an error with
+  // { found: <number>, expect: <number>, code: 'EBADSIZE' }
+})
+response.pipe(stream)
+```
+
+Caveats: this does not work with `objectMode` streams, and will throw a
+`TypeError` from the constructor if the size argument is missing or
+invalid.