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>

README.md

@@ -26,3 +26,7 @@ pip install aiohttp && python3 dashboard_studio/server/main.py
 ```
 
 Then open http://localhost:8099. The Photos widget also has fake Immich albums in this mode. To try your real Immich server, set `IMMICH_URL` and `IMMICH_API_KEY` before starting the server.
+
+## App icon
+
+`dashboard_studio/icon.png` is drawn by `tools/make_icon.py` (needs Pillow): `python3 tools/make_icon.py dashboard_studio/icon.png`.