feat(installer): add WPF installer/configurator project

Standalone WPF app (ClaudeDo.Installer) that handles full installation
and ongoing configuration of ClaudeDo. Two modes: wizard for first run,
tabbed settings panel for subsequent launches. Page-based extensibility
via IInstallerPage interface — adding new config sections requires only
one new class.

Install pipeline: dotnet publish, deploy binaries, write configs, init
DB (via SchemaInitializer from ClaudeDo.Data), register Windows Service,
create shortcuts. Dark theme matching the Avalonia app (forest teal accent).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Installer/Pages/ServicePage/ServicePageView.xaml

@@ -0,0 +1,56 @@
+<UserControl x:Class="ClaudeDo.Installer.Pages.ServicePage.ServicePageView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:ClaudeDo.Installer.Pages.ServicePage"
+             d:DataContext="{d:DesignInstance local:ServicePageViewModel}"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             mc:Ignorable="d">
+
+    <ScrollViewer VerticalScrollBarVisibility="Auto">
+        <StackPanel MaxWidth="520">
+            <TextBlock Text="Worker Service" FontSize="18" FontWeight="SemiBold" Margin="0,0,0,4"/>
+            <TextBlock Text="Configure the ClaudeDo Worker background service."
+                       Foreground="{StaticResource TextSecondaryBrush}" Margin="0,0,0,20"
+                       TextWrapping="Wrap"/>
+
+            <Label Content="SignalR Port"/>
+            <TextBox Text="{Binding SignalRPort, UpdateSourceTrigger=PropertyChanged}" Margin="0,0,0,12"/>
+
+            <Label Content="Queue Backstop Interval (ms)"/>
+            <TextBox Text="{Binding QueueBackstopIntervalMs, UpdateSourceTrigger=PropertyChanged}" Margin="0,0,0,12"/>
+
+            <Label Content="Claude CLI Path"/>
+            <Grid Margin="0,0,0,12">
+                <Grid.ColumnDefinitions>
+                    <ColumnDefinition Width="*"/>
+                    <ColumnDefinition Width="Auto"/>
+                </Grid.ColumnDefinitions>
+                <TextBox Grid.Column="0" Text="{Binding ClaudeBin, UpdateSourceTrigger=PropertyChanged}"/>
+                <Button Grid.Column="1" Content="Browse..." Command="{Binding BrowseClaudeCommand}"
+                        Margin="8,0,0,0"/>
+            </Grid>
+
+            <Separator Margin="0,4,0,12"/>
+
+            <Label Content="Service Account"/>
+            <StackPanel Margin="0,0,0,12">
+                <RadioButton Content="Local System (recommended)"
+                             IsChecked="{Binding IsLocalSystem}" Margin="0,0,0,4"/>
+                <RadioButton Content="Current User"
+                             IsChecked="{Binding IsCurrentUser}"/>
+                <TextBlock Text="Running as current user requires 'Log on as a service' privilege."
+                           Foreground="{StaticResource TextDimBrush}" FontSize="11" Margin="20,2,0,0"
+                           TextWrapping="Wrap"/>
+            </StackPanel>
+
+            <CheckBox Content="Start service automatically" IsChecked="{Binding AutoStart}" Margin="0,0,0,12"/>
+
+            <Label Content="Restart Delay (ms)"/>
+            <TextBox Text="{Binding RestartDelayMs, UpdateSourceTrigger=PropertyChanged}" Margin="0,0,0,12"/>
+
+            <TextBlock Text="{Binding ValidationError}" Foreground="{StaticResource ErrorBrush}" FontSize="11"
+                       Visibility="{Binding ValidationError, Converter={StaticResource NullToCollapsedConverter}}"/>
+        </StackPanel>
+    </ScrollViewer>
+</UserControl>