Style ToolTip for dark theme — replace cream Win98 popup

Default WPF ToolTip is cream-on-black with a thin 3D border — looks like a Win98 popup on the dark canvas. The app has dozens of tooltips on settings controls, header pills, IN-CALL bar, and per-row toggles — every one was previously rendering as the OS default.

New style: SurfaceElevated background, BorderStrong border, rounded 6px corner, monospace-friendly text wrapping at 320px so a verbose explanation doesn't stretch across the whole monitor.

Implementation note: ContentPresenter doesn't accept TextBlock.TextWrapping as an attached property — used a templated TextBlock bound directly to Content instead (every tooltip in the app passes a plain string).

src/TeamsISO.App/Themes/WildDragonTheme.xaml

@@ -823,6 +823,48 @@
         <Setter Property="BorderThickness" Value="1"/>
     </Style>
 
+    <!-- ════ ToolTip ════ -->
+    <!--
+        Default WPF ToolTips render as cream-on-black with a thin border —
+        Win98 aesthetic. Replace with a slim dark card so the dozens of
+        tooltips throughout MainWindow read as part of the same UI rather
+        than as OS popups bolted on. Wraps long tooltip text at 320px so a
+        verbose explanation doesn't stretch across a whole monitor.
+    -->
+    <Style TargetType="ToolTip">
+        <Setter Property="Background" Value="{StaticResource Wd.SurfaceElevated}"/>
+        <Setter Property="BorderBrush" Value="{StaticResource Wd.BorderStrong}"/>
+        <Setter Property="BorderThickness" Value="1"/>
+        <Setter Property="Foreground" Value="{StaticResource Wd.Text.Primary}"/>
+        <Setter Property="FontFamily" Value="{StaticResource Wd.Font.Sans}"/>
+        <Setter Property="FontSize" Value="12"/>
+        <Setter Property="Padding" Value="10,6"/>
+        <Setter Property="HasDropShadow" Value="False"/>
+        <Setter Property="Placement" Value="Bottom"/>
+        <Setter Property="VerticalOffset" Value="6"/>
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="ToolTip">
+                    <Border Background="{TemplateBinding Background}"
+                            BorderBrush="{TemplateBinding BorderBrush}"
+                            BorderThickness="{TemplateBinding BorderThickness}"
+                            CornerRadius="{StaticResource Radius.S}"
+                            Padding="{TemplateBinding Padding}"
+                            MaxWidth="320">
+                        <!-- Most tooltips in this app pass a plain string for
+                             Content; bind directly to a TextBlock so we get
+                             TextWrapping="Wrap" and respect the parent's
+                             MaxWidth. ContentPresenter wouldn't honor
+                             TextBlock.TextWrapping (not an attached prop). -->
+                        <TextBlock Text="{TemplateBinding Content}"
+                                   TextWrapping="Wrap"
+                                   Foreground="{TemplateBinding Foreground}"/>
+                    </Border>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
     <!-- ════ ContextMenu (right-click) ════ -->
     <!--
         WPF's default ContextMenu renders white-on-grey with a 3D border —