Update PWA metadata

frontend/index.html

@@ -5,6 +5,12 @@
     <link rel="icon" href="/horde.png">
     <meta name="viewport" content="width=device-width, height=device-height, initial-scale=1.0">
 
+    <!-- PWA tags -->
+    <meta name="description" content="Chat with Horde agents">
+    <link rel="apple-touch-icon" href="/apple-icon-180.png" sizes="180x180">
+    <link rel="mask-icon" href="/horde.png" color="#FFFFFF">
+    <meta name="theme-color" content="#181818">
+
     <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.7.2/css/all.min.css" rel="stylesheet">
     <!--link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.13.1/font/bootstrap-icons.min.css"-->