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/copy-anything/dist/index.es.js

@@ -0,0 +1,48 @@
+import { isArray, isPlainObject } from 'is-what';
+
+function assignProp(carry, key, newVal, originalObject, includeNonenumerable) {
+    const propType = {}.propertyIsEnumerable.call(originalObject, key)
+        ? 'enumerable'
+        : 'nonenumerable';
+    if (propType === 'enumerable')
+        carry[key] = newVal;
+    if (includeNonenumerable && propType === 'nonenumerable') {
+        Object.defineProperty(carry, key, {
+            value: newVal,
+            enumerable: false,
+            writable: true,
+            configurable: true,
+        });
+    }
+}
+/**
+ * Copy (clone) an object and all its props recursively to get rid of any prop referenced of the original object. Arrays are also cloned, however objects inside arrays are still linked.
+ *
+ * @export
+ * @template T
+ * @param {T} target Target can be anything
+ * @param {Options} [options = {}] Options can be `props` or `nonenumerable`
+ * @returns {T} the target with replaced values
+ * @export
+ */
+function copy(target, options = {}) {
+    if (isArray(target)) {
+        return target.map((item) => copy(item, options));
+    }
+    if (!isPlainObject(target)) {
+        return target;
+    }
+    const props = Object.getOwnPropertyNames(target);
+    const symbols = Object.getOwnPropertySymbols(target);
+    return [...props, ...symbols].reduce((carry, key) => {
+        if (isArray(options.props) && !options.props.includes(key)) {
+            return carry;
+        }
+        const val = target[key];
+        const newVal = copy(val, options);
+        assignProp(carry, key, newVal, target, options.nonenumerable);
+        return carry;
+    }, {});
+}
+
+export { copy };