Expand terminal filesystem, add mainframe hint cron, redirect PHP logs

- Game1 terminal: flesh out the virtual filesystem with a realistic
  spread of Linux directories/files (~70 dirs, ~140 files) so it no
  longer reads as an obviously small puzzle set, without touching any
  win-condition or rapport files.
- Add app:hints:check command + a php-cron container (BusyBox crond)
  that nudges players who haven't contacted every teammate 5 minutes
  into a session, via a new 'hint' Mercure message type.
- Log the cron command's output to var/log/cron/cron.log and rotate
  it (25MB / 90 days) via logrotate, run daily from the same crontab.
- Redirect PHP's error_log and Symfony's prod app/deprecation logs
  from stderr-only into var/log/php/*.log (kept alongside stderr),
  with the same rotation policy.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

assets/game1/filesystem/etc/crontab

@@ -0,0 +1,8 @@
+# /etc/crontab: system-wide crontab
+SHELL=/bin/sh
+PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
+
+17 *    * * *   root    cd / && run-parts --report /etc/cron.hourly
+25 6    * * *   root    test -x /usr/sbin/anacron || run-parts --report /etc/cron.daily
+47 6    * * 7   root    test -x /usr/sbin/anacron || run-parts --report /etc/cron.weekly
+52 6    1 * *   root    test -x /usr/sbin/anacron || run-parts --report /etc/cron.monthly