Dashboard Studio 1.14.1: Android app, phone menu button, install fix

- Android app (android/, built with build.sh): signs in to Home Assistant once, opens Dashboard Studio full screen, renews the ingress session; downloadable from Install as an app
- Phone dashboards: a round menu button brings back the top bar with Edit, Kiosk and Install as an app
- Install as an app explains what works per device (Android app, https for browser install, iPhone limits)
- Fixed: browser install failed because the manifest was fetched without the Home Assistant sign-in

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dashboard_studio/web/index.html

@@ -9,7 +9,8 @@
   <title>Dashboard Studio</title>
   <link rel="icon" type="image/png" href="static/favicon.png">
   <link rel="stylesheet" href="static/style.css">
-  <link rel="manifest" href="manifest.webmanifest">
+  <!-- Home Assistant only serves this app to a signed-in browser: the manifest has to be fetched with the cookie -->
+  <link rel="manifest" href="manifest.webmanifest" crossorigin="use-credentials">
   <link rel="apple-touch-icon" href="static/apple-touch-icon.png">
   <meta name="theme-color" content="#0f1526">
   <meta name="apple-mobile-web-app-capable" content="yes">
@@ -37,6 +38,7 @@
           <button id="btn-menu" class="btn icon" aria-label="More actions" aria-haspopup="menu" aria-expanded="false" title="More actions"></button>
         </span>
         <button id="btn-guest" class="btn view-only" hidden><span data-i18n>Guest mode</span></button>
+        <button id="btn-app" class="btn icon view-only" aria-label="Install as an app" title="Install as an app"></button>
         <button id="btn-kiosk" class="btn view-only label-wide" aria-label="Kiosk" title="Kiosk mode"><span data-i18n>Kiosk</span></button>
         <button id="btn-edit" class="btn primary" data-i18n>Edit</button>
       </div>
@@ -82,6 +84,7 @@
   <div id="saver" hidden aria-hidden="true"><div class="photos"><img class="ph-layer" alt=""><img class="ph-layer" alt=""><div class="ph-msg"></div></div><div class="saver-clock"><div class="time num"></div><div class="date"></div></div></div>
   <div id="doorbell" hidden role="alertdialog" aria-modal="true" aria-labelledby="db-title"><div class="db-cam"></div><div class="db-bar"><div class="db-title" id="db-title"></div><button class="btn db-close">Close</button></div></div>
   <div id="night-dim" aria-hidden="true"></div>
+  <button id="phone-menu" class="btn icon" aria-label="Menu" title="Menu"></button>
   <div id="offline-note" hidden role="status"></div>
   <div id="ptr" hidden aria-hidden="true"><svg viewBox="0 0 24 24"><path d="M20 11a8 8 0 1 0-2.3 5.7M20 4v7h-7"/></svg></div>
   <div id="announce" hidden role="alertdialog" aria-modal="true" aria-labelledby="an-title"><div class="an-card"><div class="an-ico"></div><div class="an-title" id="an-title"></div><div class="an-msg"></div><button class="btn primary an-ok">OK</button></div></div>