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/Core/PageResolver.cs

@@ -0,0 +1,17 @@
+namespace ClaudeDo.Installer.Core;
+
+public sealed class PageResolver
+{
+    private readonly IReadOnlyList<IInstallerPage> _allPages;
+
+    public PageResolver(IEnumerable<IInstallerPage> pages)
+    {
+        _allPages = pages.OrderBy(p => p.Order).ToList();
+    }
+
+    public IReadOnlyList<IInstallerPage> WizardPages =>
+        _allPages.Where(p => p.ShowInWizard).ToList();
+
+    public IReadOnlyList<IInstallerPage> SettingsPages =>
+        _allPages.Where(p => p.ShowInSettings).ToList();
+}