feat: page-based navigation shell + Tests page wizard

Replace the monolithic MainWindow with a SelectedPage-driven shell
(Dashboard / Pump / Bench / Tests / Results / Settings). The Tests
page gets the Plan -> Preconditions -> Running -> Done wizard from
ui-structure.md \u00a74, backed by a 7-item precondition gate and
shared sub-views (PhaseCardView / TestSectionView / GraphicIndicatorView)
extracted from the now-deleted monolithic TestPanelView.

New VMs / views:
- Tests wizard: TestPreconditions, PhaseCard, GraphicIndicator,
  TestSection, TestPlan, TestRunning, TestDone
- Dashboard panels: DashboardConnection, DashboardReadings,
  DashboardAlarms, InterlockBanner, ResultHistory
- Pump / bench panels: PumpIdentificationPanel, PumpLiveData,
  UnlockPanel, BenchDriveControl, BenchReadings, RelayBank,
  TemperatureControl, DtcList, AuthGate
- Dialogs: generic ConfirmDialog, UserManageDialog, UserPromptDialog

Supporting changes:
- IsOilPumpOn exposed on MainViewModel for precondition evaluation
- RequiresAuth added to TestDefinition (XML round-trip)
- BipStatusDefinition + CompletedTestRun models
- ~35 new Test.* localization keys (en + es)
- Settings moved from modal dialog to full page
- Pause / Retry / Skip stubs in TestRunningView; full spec in
  docs/gap-test-running-controls.md for follow-up implementation
- docs/ui-structure.md captures the wizard design

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Views/UserControls/InterlockBannerView.xaml

@@ -0,0 +1,47 @@
+<UserControl x:Class="HC_APTBS.Views.UserControls.InterlockBannerView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             mc:Ignorable="d"
+             d:DesignHeight="40" d:DesignWidth="800">
+    <!--
+      Soft safety interlock banner. Visible only when
+      InterlockBannerViewModel.IsVisible is true.
+      Colour switches from warning amber to critical red.
+    -->
+    <UserControl.Resources>
+        <BooleanToVisibilityConverter x:Key="BoolToVis"/>
+    </UserControl.Resources>
+
+    <Border CornerRadius="3" Padding="10,6" Margin="0,4"
+            Visibility="{Binding IsVisible, Converter={StaticResource BoolToVis}}">
+        <Border.Style>
+            <Style TargetType="Border">
+                <Setter Property="Background" Value="#FFB020"/>
+                <Style.Triggers>
+                    <DataTrigger Binding="{Binding IsCritical}" Value="True">
+                        <Setter Property="Background" Value="#D62828"/>
+                    </DataTrigger>
+                </Style.Triggers>
+            </Style>
+        </Border.Style>
+        <Grid>
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="Auto"/>
+                <ColumnDefinition Width="*"/>
+                <ColumnDefinition Width="Auto"/>
+            </Grid.ColumnDefinitions>
+            <TextBlock Grid.Column="0" Text="⚠" Foreground="White" FontSize="16"
+                       FontWeight="Bold" VerticalAlignment="Center" Margin="0,0,8,0"/>
+            <TextBlock Grid.Column="1" Text="{Binding Message}"
+                       Foreground="White" FontWeight="SemiBold" FontSize="12"
+                       VerticalAlignment="Center" TextWrapping="Wrap"/>
+            <Button Grid.Column="2" Content="{DynamicResource Common.Close}"
+                    Command="{Binding DismissCommand}"
+                    Foreground="White" Background="Transparent" BorderBrush="White"
+                    BorderThickness="1" Padding="8,2" FontSize="11"
+                    VerticalAlignment="Center"/>
+        </Grid>
+    </Border>
+</UserControl>