Add launcher debug settings, recovery & version fixes

Introduce a persistent LauncherDebugSettingsStore and wire it into ErrorWindow and SplashWindow so dev-mode and custom host path can be saved/loaded. Harden DeploymentLocator/FlexibleHostLocator to safely normalize and validate saved debug paths and log warnings for malformed values. Add a WaitingForShell startup state and recoverable-activation logic across App and LauncherFlowCoordinator (with registry updates) so Launcher can attach to an in-progress desktop shell rather than failing. Clean up ErrorDebugWindow UI/flow (WasAccepted flag, localization fixes, event wiring) and improve splash version population. Improve AppVersionProvider to trim surrounding quotes, robustly parse version.json via JsonDocument and read string properties; add unit tests for AppVersionProvider, DeploymentLocator and LauncherDebugSettingsStore. Also quote Exec commands in the csproj and harden scripts/Generate-VersionFile.ps1 (argument normalization, LiteralPath, error handling).

LanMountainDesktop.Tests/LauncherDebugSettingsStoreTests.cs

@@ -0,0 +1,50 @@
+using LanMountainDesktop.Launcher.Services;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+[Collection("LauncherDebugSettingsStore")]
+public sealed class LauncherDebugSettingsStoreTests : IDisposable
+{
+    private readonly string _tempDirectory;
+
+    public LauncherDebugSettingsStoreTests()
+    {
+        _tempDirectory = Path.Combine(Path.GetTempPath(), "LanMountainDesktop.DebugSettingsTests", Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(_tempDirectory);
+        LauncherDebugSettingsStore.ConfigBaseDirectoryOverride = _tempDirectory;
+    }
+
+    [Fact]
+    public void Load_WhenOnlyLegacyFilesExist_ReadsLegacySettings()
+    {
+        var customPath = Path.Combine(_tempDirectory, "legacy-host.exe");
+        File.WriteAllText(Path.Combine(_tempDirectory, "devmode.config"), "1");
+        File.WriteAllText(Path.Combine(_tempDirectory, "custom-host-path.config"), customPath);
+
+        var settings = LauncherDebugSettingsStore.Load();
+
+        Assert.True(settings.DevModeEnabled);
+        Assert.Equal(customPath, settings.CustomHostPath);
+    }
+
+    [Fact]
+    public void Save_WritesNewSettingsFiles()
+    {
+        var customPath = Path.Combine(_tempDirectory, "host.exe");
+
+        LauncherDebugSettingsStore.Save(new LauncherDebugSettings(true, customPath));
+
+        Assert.Equal("True", File.ReadAllText(Path.Combine(_tempDirectory, "dev-mode.flag")).Trim());
+        Assert.Equal(customPath, File.ReadAllText(Path.Combine(_tempDirectory, "custom-host-path.txt")).Trim());
+    }
+
+    public void Dispose()
+    {
+        LauncherDebugSettingsStore.ConfigBaseDirectoryOverride = null;
+        if (Directory.Exists(_tempDirectory))
+        {
+            Directory.Delete(_tempDirectory, recursive: true);
+        }
+    }
+}