ISO toggle: square corners to match the rest of the button family

Wd.Button.IsoToggle was the only button in the GUI using CornerRadius=999
(full pill). It read as a different control type from the toolbar buttons
around it (Enable all, Refresh, Presets, Stop all, Mute, Cam, Leave —
all Radius.M). The pill shape was meant to make the LIVE state visually
distinct, but the status-coded fill (cyan/coral/amber) already carries
that signal — the geometry was double-duty.

Swap the IsoToggle's CornerRadius from 999 to Radius.M so every button
in the app shares the same shape language. Status read remains via the
fill color.

src/TeamsISO.App/MainWindow.xaml

@@ -615,23 +615,27 @@
                         </DataGridTemplateColumn>
 
                         <!-- Col 5a — Per-row gear: opens the ISO override editor for this
-                             participant. Narrow (32px) so the table still fits inside a
-                             1280px window after the toggle column. -->
-                        <DataGridTemplateColumn Header="" Width="32" IsReadOnly="True">
+                             participant. We use the Unicode gear glyph (U+2699) instead
+                             of a custom Path — it renders cleanly at any size, doesn't
+                             disappear against dark rows the way 1.4px strokes do, and
+                             reads as "settings" at a glance. Header is "CFG" so the
+                             affordance is discoverable even when the row hover state
+                             isn't active. -->
+                        <DataGridTemplateColumn Header="CFG" Width="56" IsReadOnly="True">
                             <DataGridTemplateColumn.CellTemplate>
                                 <DataTemplate>
                                     <Button Style="{StaticResource Wd.Button.Ghost}"
                                             Click="OnIsoOverrideClick"
-                                            Padding="6,4"
+                                            Padding="6,2"
                                             VerticalAlignment="Center"
                                             HorizontalAlignment="Center"
-                                            ToolTip="Override output settings for this participant">
-                                        <Path Data="M 8,1 L 8,3 M 8,13 L 8,15 M 1,8 L 3,8 M 13,8 L 15,8 M 3,3 L 4.5,4.5 M 11.5,11.5 L 13,13 M 3,13 L 4.5,11.5 M 11.5,4.5 L 13,3 M 8,5.5 C 9.4,5.5 10.5,6.6 10.5,8 C 10.5,9.4 9.4,10.5 8,10.5 C 6.6,10.5 5.5,9.4 5.5,8 C 5.5,6.6 6.6,5.5 8,5.5"
-                                              Stroke="{DynamicResource Wd.Text.Secondary}"
-                                              StrokeThickness="1.4"
-                                              Fill="Transparent"
-                                              Width="14" Height="14"
-                                              Stretch="None"/>
+                                            ToolTip="Override output settings for this participant (framerate, resolution, audio)">
+                                        <TextBlock Text="&#x2699;"
+                                                   FontSize="16"
+                                                   FontFamily="Segoe UI Symbol"
+                                                   Foreground="{DynamicResource Wd.Text.Primary}"
+                                                   VerticalAlignment="Center"
+                                                   HorizontalAlignment="Center"/>
                                     </Button>
                                 </DataTemplate>
                             </DataGridTemplateColumn.CellTemplate>

src/TeamsISO.App/Themes/WildDragonTheme.xaml

@@ -319,7 +319,11 @@
         </Setter>
     </Style>
 
-    <!-- ISO toggle: pill, status-coded -->
+    <!-- ISO toggle: rounded-rect (Radius.M) to match the rest of the button
+         family, status-coded background (LIVE cyan / ERROR coral / NO SIGNAL
+         amber). Previously a full pill (CornerRadius=999); pill made the LIVE
+         indicator visually distinct from the toolbar buttons in a way that
+         read as "different control type" rather than "different state". -->
     <Style x:Key="Wd.Button.IsoToggle" TargetType="Button">
         <Setter Property="FontFamily" Value="{StaticResource Wd.Font.Sans}"/>
         <Setter Property="FontSize" Value="11"/>
@@ -340,7 +344,7 @@
                             Background="{TemplateBinding Background}"
                             BorderBrush="{TemplateBinding BorderBrush}"
                             BorderThickness="{TemplateBinding BorderThickness}"
-                            CornerRadius="999">
+                            CornerRadius="{StaticResource Radius.M}">
                         <ContentPresenter HorizontalAlignment="Center"
                                           VerticalAlignment="Center"
                                           Margin="{TemplateBinding Padding}"/>