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/ConfigModels.cs

@@ -0,0 +1,109 @@
+using System.IO;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using ClaudeDo.Data;
+
+namespace ClaudeDo.Installer.Core;
+
+/// <summary>
+/// Mirrors ClaudeDo.Worker.Config.WorkerConfig JSON shape.
+/// Keep in sync with src/ClaudeDo.Worker/Config/WorkerConfig.cs.
+/// </summary>
+public sealed class InstallerWorkerConfig
+{
+    [JsonPropertyName("db_path")]
+    public string DbPath { get; set; } = "~/.todo-app/todo.db";
+
+    [JsonPropertyName("sandbox_root")]
+    public string SandboxRoot { get; set; } = "~/.todo-app/sandbox";
+
+    [JsonPropertyName("log_root")]
+    public string LogRoot { get; set; } = "~/.todo-app/logs";
+
+    [JsonPropertyName("worktree_root_strategy")]
+    public string WorktreeRootStrategy { get; set; } = "sibling";
+
+    [JsonPropertyName("central_worktree_root")]
+    public string CentralWorktreeRoot { get; set; } = "~/.todo-app/worktrees";
+
+    [JsonPropertyName("queue_backstop_interval_ms")]
+    public int QueueBackstopIntervalMs { get; set; } = 30_000;
+
+    [JsonPropertyName("signalr_port")]
+    public int SignalRPort { get; set; } = 47_821;
+
+    [JsonPropertyName("claude_bin")]
+    public string ClaudeBin { get; set; } = "claude";
+
+    private static readonly JsonSerializerOptions ReadOpts = new()
+    {
+        ReadCommentHandling = JsonCommentHandling.Skip,
+        AllowTrailingCommas = true,
+    };
+
+    private static readonly JsonSerializerOptions WriteOpts = new()
+    {
+        WriteIndented = true,
+    };
+
+    public static InstallerWorkerConfig Load()
+    {
+        var path = Path.Combine(Paths.AppDataRoot(), "worker.config.json");
+        if (!File.Exists(path)) return new();
+        var json = File.ReadAllText(path);
+        return JsonSerializer.Deserialize<InstallerWorkerConfig>(json, ReadOpts) ?? new();
+    }
+
+    public void Save()
+    {
+        var dir = Paths.AppDataRoot();
+        Directory.CreateDirectory(dir);
+        var path = Path.Combine(dir, "worker.config.json");
+        var json = JsonSerializer.Serialize(this, WriteOpts);
+        File.WriteAllText(path, json);
+    }
+}
+
+/// <summary>
+/// Mirrors ClaudeDo.Ui.AppSettings JSON shape.
+/// Keep in sync with src/ClaudeDo.Ui/AppSettings.cs.
+/// </summary>
+public sealed class InstallerAppSettings
+{
+    public string DbPath { get; set; } = "~/.todo-app/todo.db";
+    public string SignalRUrl { get; set; } = "http://127.0.0.1:47821/hub";
+
+    private static readonly JsonSerializerOptions ReadOpts = new()
+    {
+        PropertyNameCaseInsensitive = true,
+    };
+
+    private static readonly JsonSerializerOptions WriteOpts = new()
+    {
+        WriteIndented = true,
+    };
+
+    public static InstallerAppSettings Load()
+    {
+        var path = Path.Combine(Paths.AppDataRoot(), "ui.config.json");
+        if (!File.Exists(path)) return new();
+        try
+        {
+            var json = File.ReadAllText(path);
+            return JsonSerializer.Deserialize<InstallerAppSettings>(json, ReadOpts) ?? new();
+        }
+        catch
+        {
+            return new();
+        }
+    }
+
+    public void Save()
+    {
+        var dir = Paths.AppDataRoot();
+        Directory.CreateDirectory(dir);
+        var path = Path.Combine(dir, "ui.config.json");
+        var json = JsonSerializer.Serialize(this, WriteOpts);
+        File.WriteAllText(path, json);
+    }
+}