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/Dockerfile

@@ -6,6 +6,7 @@ RUN apk add --no-cache python3 py3-aiohttp
 WORKDIR /app
 COPY server/ /app/server/
 COPY web/ /app/web/
+COPY config.yaml /app/config.yaml
 COPY run.sh /run.sh
 RUN chmod a+x /run.sh