Dashboard Studio 1.6.0: app icon, clock weather, icon-only tab rail

- App store icon (icon.png) and favicon, drawn by tools/make_icon.py
- Clock can show a weather entity with today's high and low from
  weather.get_forecasts
- Side menu gets an icon-only rail style (now the default): full height,
  centered icons, active marker, names as hover/focus tooltips; phones
  keep a labelled bottom tab bar

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

dashboard_studio/web/index.html

@@ -6,6 +6,7 @@
   <meta name="theme-color" content="#f2f2f7" media="(prefers-color-scheme: light)">
   <meta name="theme-color" content="#0f0f11" media="(prefers-color-scheme: dark)">
   <title>Dashboard Studio</title>
+  <link rel="icon" type="image/png" href="static/favicon.png">
   <link rel="stylesheet" href="static/style.css">
 </head>
 <body>