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>

android/res/drawable/ic_bg.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <gradient android:angle="270" android:startColor="#24304f" android:endColor="#0f1526" />
+</shape>