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/thingies/lib/LruTtlMap.js

@@ -0,0 +1,40 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.LruTtlMap = void 0;
+const LruMap_1 = require("./LruMap");
+class LruTtlMap extends LruMap_1.LruMap {
+    constructor() {
+        super(...arguments);
+        this.expiry = new Map();
+    }
+    clear() {
+        this.expiry.clear();
+        super.clear();
+    }
+    delete(key) {
+        this.expiry.delete(key);
+        return super.delete(key);
+    }
+    has(key, now = 0) {
+        if (!super.has(key))
+            return false;
+        const expiry = this.expiry.get(key) || 0;
+        const expired = now > expiry;
+        if (expired)
+            this.delete(key);
+        return !expired;
+    }
+    get(key, now) {
+        if (!this.has(key, now))
+            return undefined;
+        const value = super.get(key);
+        super.set(key, value);
+        return value;
+    }
+    set(key, value, expiry = Infinity) {
+        super.set(key, value);
+        this.expiry.set(key, expiry);
+        return this;
+    }
+}
+exports.LruTtlMap = LruTtlMap;