Merge branch 'v0.4-opcua' into v0.6-history

Trailing DataGridTemplateColumn had Width="Auto"; against the 2* star columns
it collapsed on first layout, clipping the Details button to a sliver. Pin to
Width="120" so the button always fits.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/Junction.App/Views/DashboardView.axaml

@@ -71,7 +71,9 @@
                               Width="Auto"
                               x:DataType="vm:MachineRowViewModel" />
 
-          <DataGridTemplateColumn Header="" Width="Auto">
+          <!-- Fixed width: a trailing Auto column collapses against the 2* star columns,
+               clipping the Details button to a sliver on first layout. -->
+          <DataGridTemplateColumn Header="" Width="120">
             <DataGridTemplateColumn.CellTemplate>
               <DataTemplate x:DataType="vm:MachineRowViewModel">
                 <Button Content="Details"