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/@angular/router/upgrade/index.d.ts

@@ -0,0 +1,61 @@
+/**
+ * @license Angular v19.2.18
+ * (c) 2010-2025 Google LLC. https://angular.io/
+ * License: MIT
+ */
+
+import { InjectionToken, ComponentRef } from '@angular/core';
+import { UpgradeModule } from '@angular/upgrade/static';
+
+/**
+ * Creates an initializer that sets up `ngRoute` integration
+ * along with setting up the Angular router.
+ *
+ * @usageNotes
+ *
+ * For standalone applications:
+ * ```ts
+ * export const appConfig: ApplicationConfig = {
+ *   providers: [RouterUpgradeInitializer],
+ * };
+ * ```
+ *
+ * For NgModule based applications:
+ * ```ts
+ * @NgModule({
+ *  imports: [
+ *   RouterModule.forRoot(SOME_ROUTES),
+ *   UpgradeModule
+ * ],
+ * providers: [
+ *   RouterUpgradeInitializer
+ * ]
+ * })
+ * export class AppModule {
+ *   ngDoBootstrap() {}
+ * }
+ * ```
+ *
+ * @publicApi
+ */
+declare const RouterUpgradeInitializer: {
+    provide: InjectionToken<readonly ((compRef: ComponentRef<any>) => void)[]>;
+    multi: boolean;
+    useFactory: (ngUpgrade: UpgradeModule) => () => void;
+    deps: (typeof UpgradeModule)[];
+};
+/**
+ * Sets up a location change listener to trigger `history.pushState`.
+ * Works around the problem that `onPopState` does not trigger `history.pushState`.
+ * Must be called *after* calling `UpgradeModule.bootstrap`.
+ *
+ * @param ngUpgrade The upgrade NgModule.
+ * @param urlType The location strategy.
+ * @see {@link /api/common/HashLocationStrategy HashLocationStrategy}
+ * @see {@link /api/common/PathLocationStrategy PathLocationStrategy}
+ *
+ * @publicApi
+ */
+declare function setUpLocationSync(ngUpgrade: UpgradeModule, urlType?: 'path' | 'hash'): void;
+
+export { RouterUpgradeInitializer, setUpLocationSync };