Dashboard Studio 1.6.1: show version, load fresh files after updates

- Version shown under About in the dashboard settings, with a link to
  the repository; /api/version reports it
- index.html is never cached and stamps the version on every asset URL,
  so browsers can't keep running old files after an update
- Open screens check the version after reconnecting and every 5 minutes
  and reload into the new version (editing only shows a message);
  pending saves are flushed first

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

dashboard_studio/web/i18n.js

@@ -242,6 +242,9 @@
     "Weather (optional)": "Weer (optioneel)", "Show today’s high and low": "Toon de hoogste en laagste temperatuur van vandaag",
     "High {0}° · Low {1}°": "Max {0}° · min {1}°", "High {0}°": "Max {0}°",
     "Menu style": "Menustijl", "icons": "Alleen pictogrammen", "labels": "Met namen",
+    "About": "Over", "Version {0}": "Versie {0}", "Source code and changes": "Broncode en wijzigingen",
+    "Dashboard Studio was updated to {0}. Reload the page to use it.": "Dashboard Studio is bijgewerkt naar {0}. Herlaad de pagina om de nieuwe versie te gebruiken.",
+    "Dashboard Studio was updated to {0}. Reloading…": "Dashboard Studio is bijgewerkt naar {0}. Opnieuw laden…",
     "Today": "Vandaag", "Tomorrow": "Morgen", "All day": "Hele dag", "Busy": "Bezet",
   };