Jump to the middle; bold jump arrows; Chicago time; demo hours 6 AM-9 PM

- Jump sheet: Top / Middle / Bottom with the Card fields arrows; the Jump
  button uses the same bold arrows.
- Container timezone defaults to America/Chicago (TZ in Dockerfile/compose).
- Demo worker follows its own business hours (Demo.BusinessHours, default
  06:00-21:00 every day) with the midnight pitstop; the simulated cycle in
  the browser shows the real worker's next run.

Config/usmt-dash.psd1

@@ -133,6 +133,15 @@
         LifecycleHours    = 24      # how long one simulated migration takes, start to finish
         PresenceSweepMinutes = 60   # completed / Skip USMT devices: hourly, like Live (the demo runs all day)
         LivePublishSeconds = 4      # publish swept rows this often during a cycle
+
+        # When the demo worker runs (outside these hours it sleeps, with the midnight pitstop),
+        # same format as Worker.BusinessHours. Set Enabled = $false to run around the clock.
+        BusinessHours     = @{
+            Enabled  = $true
+            Start    = '06:00'
+            End      = '21:00'
+            Weekdays = @(0, 1, 2, 3, 4, 5, 6)   # every day
+        }
         Verbose           = $true   # run the worker with -v style tracing
     }