Introduce HostLaunchPlan and refine launch flow

Add HostLaunchPlan/HostLaunchPlanBuilder to encapsulate host path, package root, working dir, forwarded args and env; add unit tests for builder. Refactor LauncherFlowCoordinator to use HostLaunchPlan when starting hosts, improve IPC handling and startup logic (shorter soft/hard timeouts, more frequent reconnects and shell status polling, activation recovery via existing host). Move argument formatting and environment setup into the plan, include package/working/args metadata in start attempts. Update Commands to prefer ProcessPath for launcher base directory. App and Program: start single-instance activation listener earlier and harden ActivateMainWindow to handle shell initialization state and return richer activation status codes. SingleInstanceService: signal listener readiness (ManualResetEventSlim) and wait briefly when starting, and dispose it. Various logging and minor error handling improvements.

.trae/specs/launcher-shell-hardening/launcher-coordinator-addendum.md

@@ -0,0 +1,29 @@
+# Launcher Coordinator And Always-On Tray Addendum
+
+## Launcher-to-launcher coordination
+
+- Launcher reserves startup ownership in `%LocalAppData%\LanMountainDesktop\.launcher\state\startup-attempt.json` before it starts the host process.
+- The reserved record includes `CoordinatorPid`, `CoordinatorPipeName`, `HeartbeatAtUtc`, `PublicIpcConnected`, `ShellStatus`, and `ReservedBeforeHostStart`.
+- Only the active coordinator may call `Process.Start()` for the host. Secondary Launchers attach to the coordinator pipe and request desktop activation or status.
+- If the coordinator heartbeat is newer than `10s` and the coordinator pid is alive, a new Launcher must not take over.
+- If the coordinator is stale, the next Launcher may take over the same pending attempt instead of creating a second host attempt.
+- Normal launches probe Host Public IPC first. If a host is already running, Launcher activates that instance and exits without starting another host.
+
+## Finer shell status
+
+- Public shell IPC exposes `GetShellStatusAsync()`, `ActivateMainWindowWithStatusAsync()`, `EnsureTrayReadyAsync()`, and `EnsureTaskbarEntryAsync()`.
+- `PublicShellStatus` separates process, shell state, main-window visibility, tray health, taskbar-entry health, and Public IPC readiness.
+- Launcher success/failure details must include coordinator pid, attempt id, host pid, Public IPC status, tray state, and taskbar usability when available.
+
+## Always-on tray and taskbar repair
+
+- The tray icon and menu are mandatory application-liveness indicators and are not controlled by user settings.
+- Tray watchdog starts during shell initialization and keeps running until application exit.
+- `ShowInTaskbar=true` means hidden/background states prefer `MinimizedToTaskbar`; it never disables the tray.
+- `ShowInTaskbar=false` is the only mode that may enter pure `TrayOnly`, and only after `TrayReady`.
+- When taskbar entry is requested but missing, shell repair recreates or shows the main window minimized with `ShowInTaskbar=true` while keeping the tray visible.
+
+## Regression coverage
+
+- Unit tests cover active coordinator rejection, stale heartbeat takeover, and host-pid assignment after a reserved attempt.
+- Manual QA still needs multi-process Launcher concurrency and real tray loss simulation on Windows.

.trae/specs/launcher-shell-hardening/startup-visuals-addendum.md

@@ -0,0 +1,37 @@
+# Launcher Slow-Startup And Startup Visual Addendum
+
+## New startup timing contract
+
+- `30s` is a soft timeout, not a failure threshold.
+- After `30s`, if the desktop process is still alive or Public IPC is connected, Launcher must stay in a waiting state and must not start another host process.
+- `120s` is the hard timeout.
+- Before returning `desktop_not_visible`, Launcher must attempt one foreground recovery through `ActivateMainWindowAsync()`.
+
+## Startup attempt de-duplication
+
+- Launcher persists the current startup attempt in `%LocalAppData%\LanMountainDesktop\.launcher\state\startup-attempt.json`.
+- A second Launcher process must attach to a live pending attempt instead of calling `Process.Start()` again.
+- Closing the splash window does not cancel startup; it transitions the attempt into detached waiting and preserves recovery state for the next Launcher run.
+
+## Startup visual modes
+
+- `EnableSlideTransition = true` forces `StartupVisualMode.SlideSplash` and automatically disables fade.
+- `EnableSlideTransition = false && EnableFadeTransition = false` resolves to `StartupVisualMode.StaticSplash`.
+- `EnableSlideTransition = false && EnableFadeTransition = true` resolves to `StartupVisualMode.Fade`.
+
+## UX safeguards
+
+- If the host process is still alive at failure time, the failure dialog must prefer:
+  - `Activate`
+  - `Wait`
+  - `Open Logs`
+  - `Exit`
+- Retry is only valid when Launcher is not about to create a duplicate desktop process.
+
+## Launcher coordinator guard
+
+- Startup attempts are now reserved before host launch, so concurrent Launchers cannot all reach `Process.Start()`.
+- A live coordinator is identified by `CoordinatorPid`, `CoordinatorPipeName`, and a heartbeat newer than `10s`.
+- Secondary Launchers send `activate-desktop` or `attach` to the coordinator pipe and then exit with the coordinator status.
+- If Host Public IPC is already available during a normal launch, Launcher activates the existing desktop and does not start a new host process.
+- Public shell status now reports tray readiness and taskbar-entry usability separately, allowing Launcher to distinguish "running but hidden" from "not recoverable".

.trae/specs/launcher-shell-hardening/tray-menu-shutdown-addendum.md

@@ -0,0 +1,17 @@
+# Tray Menu Shutdown Addendum
+
+## Requirements
+
+- Tray menu `Exit App` must commit an irreversible host shutdown request.
+- Once shutdown is committed, tray menu actions must not reopen the desktop, settings window, or component library.
+- Shutdown cleanup must release Public IPC, plugin runtime, tray icon, fused desktop edit UI, telemetry resources, and the single-instance lock before the forced-exit deadline.
+- Forced process termination must be scheduled when the shutdown request is accepted, not only after Avalonia lifetime exit.
+- Restart must preserve `RestartRequested` intent and must not route through an exit path that overwrites it.
+- Fused desktop component library menu activation must reuse the existing library window and must exit edit mode if opening fails.
+
+## Acceptance
+
+- Selecting `Exit App` from the tray leaves no background host process and allows a later Launcher start to acquire the single-instance lock.
+- Selecting `Restart App` starts the Launcher or upgrade helper once, then shuts down the old host as a restart.
+- Repeated tray clicks during shutdown are ignored and logged.
+- Repeated component-library clicks focus the existing window instead of opening duplicates.

LanMountainDesktop.Launcher/App.axaml.cs

@@ -1,3 +1,4 @@
+using System.Diagnostics;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
@@ -5,7 +6,11 @@ using Avalonia.Markup.Xaml;
 using Avalonia.Threading;
 using LanMountainDesktop.Launcher.Models;
 using LanMountainDesktop.Launcher.Services;
+using LanMountainDesktop.Launcher.Services.Ipc;
 using LanMountainDesktop.Launcher.Views;
+using LanMountainDesktop.Shared.Contracts.Launcher;
+using LanMountainDesktop.Shared.IPC;
+using LanMountainDesktop.Shared.IPC.Abstractions.Services;
 
 namespace LanMountainDesktop.Launcher;
 
@@ -52,7 +57,7 @@ public partial class App : Application
             }
             else
             {
-                var splashWindow = new SplashWindow();
+                var splashWindow = CreateSplashWindow();
                 splashWindow.Show();
                 _ = RunCoordinatorWithSplashAsync(desktop, context, splashWindow);
             }
@@ -68,7 +73,7 @@ public partial class App : Application
             case "preview-splash":
             {
                 Logger.Info("Preview command: splash.");
-                var splashWindow = new SplashWindow();
+                var splashWindow = CreateSplashWindow();
                 splashWindow.SetDebugMode(true);
                 splashWindow.Show();
                 _ = SimulateSplashPreviewAsync(desktop, splashWindow);
@@ -112,6 +117,28 @@ public partial class App : Application
         }
     }
 
+    private static SplashWindow CreateSplashWindow()
+    {
+        var preferences = StartupVisualPreferencesResolver.Resolve();
+        var window = new SplashWindow(preferences.Mode);
+        TrySetSplashVersionInfo(window, LauncherRuntimeContext.Current);
+        return window;
+    }
+
+    private static void TrySetSplashVersionInfo(SplashWindow window, CommandContext context)
+    {
+        try
+        {
+            var appRoot = Commands.ResolveAppRoot(context);
+            var versionInfo = new DeploymentLocator(appRoot).GetVersionInfo();
+            window.SetVersionInfo(versionInfo.Version, versionInfo.Codename);
+        }
+        catch (Exception ex)
+        {
+            Logger.Warn($"Failed to set splash version info before coordinator start: {ex.Message}");
+        }
+    }
+
     private async Task SimulateSplashPreviewAsync(IClassicDesktopStyleApplicationLifetime desktop, SplashWindow window)
     {
         var stages = new[] { "initializing", "update", "plugins", "launch", "ready" };
@@ -172,53 +199,330 @@ public partial class App : Application
         SplashWindow splashWindow)
     {
         LauncherResult result;
+        SplashWindow? currentSplashWindow = splashWindow;
+        var appRoot = Commands.ResolveAppRoot(context);
+        var startupAttemptRegistry = new StartupAttemptRegistry();
+        var coordinatorPipeName = LauncherCoordinatorIpcServer.CreatePipeName();
+        var successPolicy = LauncherFlowCoordinator.ResolveSuccessPolicyKey(context);
 
-        try
+        if (!startupAttemptRegistry.TryReserveCoordinator(
+                context.LaunchSource,
+                successPolicy,
+                coordinatorPipeName,
+                out var reservedAttempt,
+                out var activeCoordinatorAttempt))
         {
-            var appRoot = Commands.ResolveAppRoot(context);
-            Logger.Info(
-                $"Coordinator start. Command='{context.Command}'; AppRoot='{appRoot}'; " +
-                $"IsDebugMode={context.IsDebugMode}; LaunchSource='{context.LaunchSource}'; " +
-                $"ResultPath='{context.GetOption("result") ?? "<none>"}'.");
-
-            var deploymentLocator = new DeploymentLocator(appRoot);
-            var coordinator = new LauncherFlowCoordinator(
+            result = await AttachToExistingCoordinatorAsync(
                 context,
-                deploymentLocator,
-                new OobeStateService(appRoot),
-                new UpdateEngineService(deploymentLocator),
-                new PluginInstallerService());
+                currentSplashWindow,
+                activeCoordinatorAttempt).ConfigureAwait(false);
 
-            result = await coordinator.RunAsync(splashWindow).ConfigureAwait(false);
+            Logger.Info($"Secondary launcher completed. Success={result.Success}; Code='{result.Code}'.");
+            await WriteLauncherResultAsync(context, result).ConfigureAwait(false);
+
+            Environment.ExitCode = result.Success ? 0 : 1;
+            await Dispatcher.UIThread.InvokeAsync(() => desktop.Shutdown(Environment.ExitCode), DispatcherPriority.Background);
+            return;
         }
-        catch (Exception ex)
+
+        using var coordinatorServer = new LauncherCoordinatorIpcServer(
+            coordinatorPipeName,
+            BuildCoordinatorStatusFromAttempt(reservedAttempt),
+            HandleCoordinatorRequestAsync,
+            startupAttemptRegistry.UpdateOwnedCoordinatorHeartbeat);
+        coordinatorServer.Start();
+
+        while (true)
         {
-            Logger.Error("Coordinator threw an unhandled exception.", ex);
-            result = new LauncherResult
+            try
             {
-                Success = false,
-                Stage = "launch",
-                Code = "exception",
-                Message = $"Launcher failed: {ex.Message}",
-                ErrorMessage = ex.ToString()
-            };
+                Logger.Info(
+                    $"Coordinator start. Command='{context.Command}'; AppRoot='{appRoot}'; " +
+                    $"IsDebugMode={context.IsDebugMode}; LaunchSource='{context.LaunchSource}'; " +
+                    $"ResultPath='{context.GetOption("result") ?? "<none>"}'.");
+
+                var deploymentLocator = new DeploymentLocator(appRoot);
+                var coordinator = new LauncherFlowCoordinator(
+                    context,
+                    deploymentLocator,
+                    new OobeStateService(appRoot),
+                    new UpdateEngineService(deploymentLocator),
+                    new PluginInstallerService(),
+                    startupAttemptRegistry,
+                    coordinatorServer);
+
+                result = await coordinator.RunAsync(currentSplashWindow).ConfigureAwait(false);
+            }
+            catch (Exception ex)
+            {
+                Logger.Error("Coordinator threw an unhandled exception.", ex);
+                result = new LauncherResult
+                {
+                    Success = false,
+                    Stage = "launch",
+                    Code = "exception",
+                    Message = $"Launcher failed: {ex.Message}",
+                    ErrorMessage = ex.ToString()
+                };
+            }
+
+            if (result.Success ||
+                result.Code == "host_not_found" ||
+                (!string.Equals(result.Stage, "launch", StringComparison.OrdinalIgnoreCase) &&
+                 !string.Equals(result.Stage, "launchHost", StringComparison.OrdinalIgnoreCase)))
+            {
+                break;
+            }
+
+            var failureAction = await ShowFailureWindowAsync(result).ConfigureAwait(false);
+            if (failureAction == ErrorWindowResult.Exit)
+            {
+                break;
+            }
+
+            if (failureAction == ErrorWindowResult.ActivateExisting &&
+                await TryActivateExistingInstanceAsync().ConfigureAwait(false))
+            {
+                result = new LauncherResult
+                {
+                    Success = true,
+                    Stage = "launch",
+                    Code = "activation_requested",
+                    Message = "Launcher activated the existing desktop instance.",
+                    Details = result.Details
+                };
+                break;
+            }
+
+            currentSplashWindow = CreateSplashWindow();
+            currentSplashWindow.Show();
         }
 
         Logger.Info($"Coordinator completed. Success={result.Success}; Stage='{result.Stage}'; Code='{result.Code}'.");
         await WriteLauncherResultAsync(context, result).ConfigureAwait(false);
 
-        if (!result.Success &&
-            result.Code is not "host_not_found" &&
-            (string.Equals(result.Stage, "launch", StringComparison.OrdinalIgnoreCase) ||
-             string.Equals(result.Stage, "launchHost", StringComparison.OrdinalIgnoreCase)))
-        {
-            await ShowFailureWindowAsync(result).ConfigureAwait(false);
-        }
-
         Environment.ExitCode = result.Success ? 0 : 1;
         await Dispatcher.UIThread.InvokeAsync(() => desktop.Shutdown(Environment.ExitCode), DispatcherPriority.Background);
     }
 
+    private static async Task<LauncherResult> AttachToExistingCoordinatorAsync(
+        CommandContext context,
+        SplashWindow? splashWindow,
+        StartupAttemptRecord? activeCoordinatorAttempt)
+    {
+        var reporter = splashWindow as ISplashStageReporter;
+        reporter?.Report("activation", "Connecting to the active launcher...");
+
+        if (activeCoordinatorAttempt is not null &&
+            !string.IsNullOrWhiteSpace(activeCoordinatorAttempt.CoordinatorPipeName))
+        {
+            var command = string.Equals(context.LaunchSource, "restart", StringComparison.OrdinalIgnoreCase)
+                ? LauncherCoordinatorCommands.Attach
+                : LauncherCoordinatorCommands.ActivateDesktop;
+            var request = new LauncherCoordinatorRequest
+            {
+                Command = command,
+                LaunchSource = context.LaunchSource,
+                SuccessPolicy = LauncherFlowCoordinator.ResolveSuccessPolicyKey(context)
+            };
+
+            var response = await new LauncherCoordinatorIpcClient()
+                .SendAsync(activeCoordinatorAttempt.CoordinatorPipeName, request, TimeSpan.FromSeconds(2))
+                .ConfigureAwait(false);
+
+            if (response is not null)
+            {
+                reporter?.Report("activation", response.Message);
+                await DismissSplashIfNeededAsync(splashWindow).ConfigureAwait(false);
+                var success = response.Accepted ||
+                              IsRecoverableActivationFailure(response.ActivationResult, response.Status);
+                return new LauncherResult
+                {
+                    Success = success,
+                    Stage = "launch",
+                    Code = success && !response.Accepted ? "attached_to_launcher_coordinator" : response.Code,
+                    Message = success && !response.Accepted
+                        ? "Attached to the active Launcher coordinator; desktop startup is still in progress."
+                        : response.Message,
+                    Details = BuildCoordinatorResultDetails(response.Status, response.ActivationResult)
+                };
+            }
+        }
+
+        var activation = await TryActivateExistingInstanceWithStatusAsync(TimeSpan.FromSeconds(2)).ConfigureAwait(false);
+        if (activation is not null)
+        {
+            reporter?.Report("activation", activation.Message);
+            await DismissSplashIfNeededAsync(splashWindow).ConfigureAwait(false);
+            var success = activation.Accepted || IsRecoverableActivationFailure(activation, null);
+            return new LauncherResult
+            {
+                Success = success,
+                Stage = "launch",
+                Code = activation.Accepted
+                    ? "existing_host_activated"
+                    : success
+                        ? "existing_host_startup_pending"
+                        : "existing_host_activation_failed",
+                Message = success && !activation.Accepted
+                    ? "Existing desktop process is still starting; Launcher attached without starting another process."
+                    : activation.Message,
+                Details = BuildCoordinatorResultDetails(null, activation)
+            };
+        }
+
+        await DismissSplashIfNeededAsync(splashWindow).ConfigureAwait(false);
+        return new LauncherResult
+        {
+            Success = false,
+            Stage = "launch",
+            Code = "launcher_coordinator_unavailable",
+            Message = "Another Launcher is coordinating startup, but it did not respond in time.",
+            Details = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
+            {
+                ["activeCoordinatorPid"] = activeCoordinatorAttempt?.CoordinatorPid.ToString() ?? string.Empty,
+                ["activeCoordinatorPipeName"] = activeCoordinatorAttempt?.CoordinatorPipeName ?? string.Empty,
+                ["activeAttemptId"] = activeCoordinatorAttempt?.AttemptId ?? string.Empty,
+                ["activeHostPid"] = activeCoordinatorAttempt?.HostPid.ToString() ?? string.Empty
+            }
+        };
+    }
+
+    private static async Task<LauncherCoordinatorResponse> HandleCoordinatorRequestAsync(
+        LauncherCoordinatorRequest request,
+        LauncherCoordinatorStatus status)
+    {
+        if (string.Equals(request.Command, LauncherCoordinatorCommands.ActivateDesktop, StringComparison.OrdinalIgnoreCase))
+        {
+            var activation = await TryActivateExistingInstanceWithStatusAsync(TimeSpan.FromSeconds(2)).ConfigureAwait(false);
+            if (activation is not null)
+            {
+                if (!activation.Accepted && IsRecoverableActivationFailure(activation, status))
+                {
+                    return new LauncherCoordinatorResponse
+                    {
+                        Accepted = true,
+                        Code = "attached_to_launcher_coordinator",
+                        Message = "Attached to the active Launcher coordinator; desktop startup is still in progress.",
+                        Status = status,
+                        ActivationResult = activation
+                    };
+                }
+
+                return new LauncherCoordinatorResponse
+                {
+                    Accepted = activation.Accepted,
+                    Code = activation.Accepted ? "existing_host_activated" : "existing_host_activation_failed",
+                    Message = activation.Message,
+                    Status = status,
+                    ActivationResult = activation
+                };
+            }
+
+            return new LauncherCoordinatorResponse
+            {
+                Accepted = true,
+                Code = "attached_to_launcher_coordinator",
+                Message = "Attached to the active Launcher coordinator; desktop startup is still in progress.",
+                Status = status
+            };
+        }
+
+        return new LauncherCoordinatorResponse
+        {
+            Accepted = true,
+            Code = "attached_to_launcher_coordinator",
+            Message = "Attached to the active Launcher coordinator.",
+            Status = status
+        };
+    }
+
+    private static LauncherCoordinatorStatus BuildCoordinatorStatusFromAttempt(StartupAttemptRecord attempt)
+    {
+        return new LauncherCoordinatorStatus
+        {
+            AttemptId = attempt.AttemptId,
+            CoordinatorPid = Environment.ProcessId,
+            HostPid = attempt.HostPid,
+            HostProcessAlive = TryGetLiveProcess(attempt.HostPid),
+            LaunchSource = attempt.LaunchSource,
+            SuccessPolicy = attempt.SuccessPolicy,
+            LastObservedStage = attempt.LastObservedStage,
+            LastObservedMessage = attempt.LastObservedMessage,
+            PublicIpcConnected = attempt.PublicIpcConnected || attempt.IpcConnected,
+            State = attempt.State.ToString(),
+            SoftTimeoutShown = attempt.State is StartupAttemptState.SoftTimeout or StartupAttemptState.DetachedWaiting,
+            Completed = attempt.State is StartupAttemptState.Succeeded or StartupAttemptState.Failed,
+            Succeeded = attempt.State == StartupAttemptState.Succeeded,
+            UpdatedAtUtc = attempt.UpdatedAtUtc
+        };
+    }
+
+    private static bool IsRecoverableActivationFailure(
+        PublicShellActivationResult? activation,
+        LauncherCoordinatorStatus? status)
+    {
+        if (activation is { Accepted: true })
+        {
+            return false;
+        }
+
+        if (status is { Completed: false, HostProcessAlive: true })
+        {
+            return true;
+        }
+
+        var shellStatus = activation?.Status;
+        if (shellStatus is null || !shellStatus.PublicIpcReady)
+        {
+            return false;
+        }
+
+        return !shellStatus.MainWindowOpened ||
+               !shellStatus.DesktopVisible ||
+               string.Equals(activation?.Code, "shell_not_ready", StringComparison.OrdinalIgnoreCase) ||
+               string.Equals(activation?.Code, "startup_pending", StringComparison.OrdinalIgnoreCase);
+    }
+
+    private static Dictionary<string, string> BuildCoordinatorResultDetails(
+        LauncherCoordinatorStatus? status,
+        PublicShellActivationResult? activation)
+    {
+        var details = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
+        {
+            ["coordinatorPid"] = status?.CoordinatorPid.ToString() ?? string.Empty,
+            ["coordinatorAttemptId"] = status?.AttemptId ?? string.Empty,
+            ["hostPid"] = status?.HostPid.ToString() ?? activation?.Status.ProcessId.ToString() ?? string.Empty,
+            ["hostProcessAlive"] = status?.HostProcessAlive.ToString() ?? string.Empty,
+            ["publicIpcConnected"] = (status?.PublicIpcConnected ?? activation is not null).ToString(),
+            ["startupStage"] = status?.LastObservedStage.ToString() ?? string.Empty,
+            ["startupState"] = status?.State ?? string.Empty,
+            ["activationAccepted"] = activation?.Accepted.ToString() ?? string.Empty,
+            ["shellState"] = activation?.Status.ShellState ?? status?.ShellStatus?.ShellState ?? string.Empty,
+            ["trayState"] = activation?.Status.Tray.State ?? status?.ShellStatus?.Tray.State ?? string.Empty,
+            ["taskbarUsable"] = activation?.Status.Taskbar.IsUsable.ToString() ?? status?.ShellStatus?.Taskbar.IsUsable.ToString() ?? string.Empty
+        };
+
+        return details;
+    }
+
+    private static async Task DismissSplashIfNeededAsync(SplashWindow? splashWindow)
+    {
+        if (splashWindow is null)
+        {
+            return;
+        }
+
+        try
+        {
+            await splashWindow.DismissAsync().ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Warn($"Failed to dismiss splash after coordinator attach: {ex.Message}");
+        }
+    }
+
     private static async Task WriteLauncherResultAsync(CommandContext context, LauncherResult result)
     {
         var resultPath = context.GetOption("result");
@@ -238,15 +542,31 @@ public partial class App : Application
         }
     }
 
-    private static async Task ShowFailureWindowAsync(LauncherResult result)
+    private static async Task<ErrorWindowResult> ShowFailureWindowAsync(LauncherResult result)
     {
         ErrorWindow? errorWindow = null;
+        var hostProcessAlive = result.Details.TryGetValue("hostProcessAlive", out var hostProcessAliveText) &&
+                               bool.TryParse(hostProcessAliveText, out var hostProcessAliveValue) &&
+                               hostProcessAliveValue;
+        var hostPid = result.Details.TryGetValue("hostPid", out var hostPidText) &&
+                      int.TryParse(hostPidText, out var parsedPid)
+            ? parsedPid
+            : (int?)null;
 
         await Dispatcher.UIThread.InvokeAsync(() =>
         {
             try
             {
                 errorWindow = new ErrorWindow();
+                if (hostProcessAlive)
+                {
+                    errorWindow.ConfigureForRunningHostFailure(hostPid);
+                }
+                else
+                {
+                    errorWindow.ConfigureForGenericFailure(allowRetry: true);
+                }
+
                 errorWindow.SetErrorMessage(
                     $"Failed to start LanMountainDesktop.\n\nStage: {result.Stage}\nCode: {result.Code}\n\n{result.Message}");
                 errorWindow.Show();
@@ -259,16 +579,76 @@ public partial class App : Application
 
         if (errorWindow is null)
         {
-            return;
+            return ErrorWindowResult.Exit;
         }
 
         try
         {
-            await errorWindow.WaitForChoiceAsync().ConfigureAwait(false);
+            return await errorWindow.WaitForChoiceAsync().ConfigureAwait(false);
         }
         catch (Exception ex)
         {
             Logger.Error("Failure window closed unexpectedly.", ex);
+            return ErrorWindowResult.Exit;
+        }
+    }
+
+    private static async Task<bool> TryActivateExistingInstanceAsync()
+    {
+        var activation = await TryActivateExistingInstanceWithStatusAsync(TimeSpan.FromSeconds(5)).ConfigureAwait(false);
+        return activation?.Accepted == true;
+    }
+
+    private static async Task<PublicShellActivationResult?> TryActivateExistingInstanceWithStatusAsync(TimeSpan timeout)
+    {
+        try
+        {
+            using var ipcClient = new LanMountainDesktopIpcClient();
+            var connectTask = ipcClient.ConnectAsync();
+            var completedTask = await Task.WhenAny(connectTask, Task.Delay(timeout)).ConfigureAwait(false);
+            if (completedTask != connectTask)
+            {
+                return null;
+            }
+
+            await connectTask.ConfigureAwait(false);
+            if (!ipcClient.IsConnected)
+            {
+                return null;
+            }
+
+            var shellProxy = ipcClient.CreateProxy<IPublicShellControlService>();
+            var activationTask = shellProxy.ActivateMainWindowWithStatusAsync();
+            completedTask = await Task.WhenAny(activationTask, Task.Delay(timeout)).ConfigureAwait(false);
+            if (completedTask != activationTask)
+            {
+                return null;
+            }
+
+            return await activationTask.ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Warn($"Failed to activate the existing desktop instance: {ex.Message}");
+            return null;
+        }
+    }
+
+    private static bool TryGetLiveProcess(int processId)
+    {
+        if (processId <= 0)
+        {
+            return false;
+        }
+
+        try
+        {
+            using var process = Process.GetProcessById(processId);
+            return !process.HasExited;
+        }
+        catch
+        {
+            return false;
         }
     }
 

LanMountainDesktop.Launcher/AppJsonContext.cs

@@ -3,6 +3,7 @@ using System.Text.Json.Serialization;
 using LanMountainDesktop.Launcher.Models;
 using LanMountainDesktop.Launcher.Services;
 using LanMountainDesktop.Shared.Contracts.Launcher;
+using LanMountainDesktop.Shared.IPC.Abstractions.Services;
 
 namespace LanMountainDesktop.Launcher;
 
@@ -20,6 +21,13 @@ namespace LanMountainDesktop.Launcher;
 [JsonSerializable(typeof(SnapshotMetadata))]
 [JsonSerializable(typeof(AppVersionInfo))]
 [JsonSerializable(typeof(StartupProgressMessage))]
+[JsonSerializable(typeof(LauncherCoordinatorRequest))]
+[JsonSerializable(typeof(LauncherCoordinatorResponse))]
+[JsonSerializable(typeof(LauncherCoordinatorStatus))]
+[JsonSerializable(typeof(PublicShellStatus))]
+[JsonSerializable(typeof(PublicTrayStatus))]
+[JsonSerializable(typeof(PublicTaskbarStatus))]
+[JsonSerializable(typeof(PublicShellActivationResult))]
 [JsonSerializable(typeof(LauncherResult))]
 [JsonSerializable(typeof(HostDiscoveryConfig))]
 [JsonSerializable(typeof(PluginManifest))]

LanMountainDesktop.Launcher/LanMountainDesktop.Launcher.csproj

@@ -35,6 +35,7 @@
     <None Include="Assets\public-key.pem" CopyToOutputDirectory="PreserveNewest" />
     <!-- Avalonia 资源文件 -->
     <AvaloniaResource Include="Assets\logo.ico" />
+    <AvaloniaResource Include="..\LanMountainDesktop\Assets\logo_nightly.png" Link="Assets\logo_nightly.png" />
   </ItemGroup>
 
   <Target Name="CopyPublicKeyToLauncherDir" AfterTargets="Build">

LanMountainDesktop.Launcher/Models/LauncherCoordinatorMessages.cs

@@ -0,0 +1,96 @@
+using System.Text.Json.Serialization;
+using LanMountainDesktop.Shared.Contracts.Launcher;
+using LanMountainDesktop.Shared.IPC.Abstractions.Services;
+
+namespace LanMountainDesktop.Launcher.Models;
+
+internal static class LauncherCoordinatorCommands
+{
+    public const string Attach = "attach";
+    public const string ActivateDesktop = "activate-desktop";
+    public const string GetStatus = "get-status";
+}
+
+internal sealed class LauncherCoordinatorRequest
+{
+    [JsonPropertyName("requestId")]
+    public string RequestId { get; init; } = Guid.NewGuid().ToString("N");
+
+    [JsonPropertyName("command")]
+    public string Command { get; init; } = LauncherCoordinatorCommands.Attach;
+
+    [JsonPropertyName("launcherPid")]
+    public int LauncherPid { get; init; } = Environment.ProcessId;
+
+    [JsonPropertyName("launchSource")]
+    public string LaunchSource { get; init; } = string.Empty;
+
+    [JsonPropertyName("successPolicy")]
+    public string SuccessPolicy { get; init; } = string.Empty;
+}
+
+internal sealed class LauncherCoordinatorResponse
+{
+    [JsonPropertyName("accepted")]
+    public bool Accepted { get; init; }
+
+    [JsonPropertyName("code")]
+    public string Code { get; init; } = string.Empty;
+
+    [JsonPropertyName("message")]
+    public string Message { get; init; } = string.Empty;
+
+    [JsonPropertyName("status")]
+    public LauncherCoordinatorStatus? Status { get; init; }
+
+    [JsonPropertyName("activationResult")]
+    public PublicShellActivationResult? ActivationResult { get; init; }
+}
+
+internal sealed class LauncherCoordinatorStatus
+{
+    [JsonPropertyName("attemptId")]
+    public string AttemptId { get; init; } = string.Empty;
+
+    [JsonPropertyName("coordinatorPid")]
+    public int CoordinatorPid { get; init; } = Environment.ProcessId;
+
+    [JsonPropertyName("hostPid")]
+    public int HostPid { get; init; }
+
+    [JsonPropertyName("hostProcessAlive")]
+    public bool HostProcessAlive { get; init; }
+
+    [JsonPropertyName("launchSource")]
+    public string LaunchSource { get; init; } = string.Empty;
+
+    [JsonPropertyName("successPolicy")]
+    public string SuccessPolicy { get; init; } = string.Empty;
+
+    [JsonPropertyName("lastObservedStage")]
+    public StartupStage LastObservedStage { get; init; } = StartupStage.Initializing;
+
+    [JsonPropertyName("lastObservedMessage")]
+    public string LastObservedMessage { get; init; } = string.Empty;
+
+    [JsonPropertyName("publicIpcConnected")]
+    public bool PublicIpcConnected { get; init; }
+
+    [JsonPropertyName("state")]
+    public string State { get; init; } = string.Empty;
+
+    [JsonPropertyName("softTimeoutShown")]
+    public bool SoftTimeoutShown { get; init; }
+
+    [JsonPropertyName("completed")]
+    public bool Completed { get; init; }
+
+    [JsonPropertyName("succeeded")]
+    public bool Succeeded { get; init; }
+
+    [JsonPropertyName("shellStatus")]
+    public PublicShellStatus? ShellStatus { get; init; }
+
+    [JsonPropertyName("updatedAtUtc")]
+    public DateTimeOffset UpdatedAtUtc { get; init; } = DateTimeOffset.UtcNow;
+}

LanMountainDesktop.Launcher/Models/StartupAttemptRecord.cs

@@ -0,0 +1,65 @@
+using System.Text.Json.Serialization;
+using LanMountainDesktop.Shared.Contracts.Launcher;
+
+namespace LanMountainDesktop.Launcher.Models;
+
+internal enum StartupAttemptState
+{
+    Pending,
+    SoftTimeout,
+    DetachedWaiting,
+    Succeeded,
+    Failed,
+    WaitingForShell
+}
+
+internal sealed class StartupAttemptRecord
+{
+    [JsonPropertyName("attemptId")]
+    public string AttemptId { get; set; } = Guid.NewGuid().ToString("N");
+
+    [JsonPropertyName("hostPid")]
+    public int HostPid { get; set; }
+
+    [JsonPropertyName("coordinatorPid")]
+    public int CoordinatorPid { get; set; }
+
+    [JsonPropertyName("coordinatorPipeName")]
+    public string CoordinatorPipeName { get; set; } = string.Empty;
+
+    [JsonPropertyName("startedAtUtc")]
+    public DateTimeOffset StartedAtUtc { get; set; } = DateTimeOffset.UtcNow;
+
+    [JsonPropertyName("updatedAtUtc")]
+    public DateTimeOffset UpdatedAtUtc { get; set; } = DateTimeOffset.UtcNow;
+
+    [JsonPropertyName("heartbeatAtUtc")]
+    public DateTimeOffset HeartbeatAtUtc { get; set; } = DateTimeOffset.UtcNow;
+
+    [JsonPropertyName("launchSource")]
+    public string LaunchSource { get; set; } = string.Empty;
+
+    [JsonPropertyName("successPolicy")]
+    public string SuccessPolicy { get; set; } = string.Empty;
+
+    [JsonPropertyName("lastObservedStage")]
+    public StartupStage LastObservedStage { get; set; } = StartupStage.Initializing;
+
+    [JsonPropertyName("lastObservedMessage")]
+    public string LastObservedMessage { get; set; } = string.Empty;
+
+    [JsonPropertyName("ipcConnected")]
+    public bool IpcConnected { get; set; }
+
+    [JsonPropertyName("publicIpcConnected")]
+    public bool PublicIpcConnected { get; set; }
+
+    [JsonPropertyName("shellStatus")]
+    public string ShellStatus { get; set; } = string.Empty;
+
+    [JsonPropertyName("reservedBeforeHostStart")]
+    public bool ReservedBeforeHostStart { get; set; }
+
+    [JsonPropertyName("state")]
+    public StartupAttemptState State { get; set; } = StartupAttemptState.Pending;
+}

LanMountainDesktop.Launcher/Services/Commands.cs

@@ -166,7 +166,10 @@ internal static class Commands
             return Path.GetFullPath(configured);
         }
 
-        var baseDir = AppContext.BaseDirectory;
+        var launcherDir = Path.GetDirectoryName(Environment.ProcessPath);
+        var baseDir = Path.GetFullPath(!string.IsNullOrWhiteSpace(launcherDir)
+            ? launcherDir
+            : AppContext.BaseDirectory);
         
         // 发布版结构：Launcher 和 app-* 目录在同一目录
         // 检查当前目录是否有 app-* 子目录（发布版）

LanMountainDesktop.Launcher/Services/DeploymentLocator.cs

@@ -204,12 +204,16 @@ internal sealed class DeploymentLocator
             var savedCustomPath = Views.ErrorWindow.GetSavedCustomHostPath();
             if (!string.IsNullOrWhiteSpace(savedCustomPath))
             {
-                var fullSavedPath = Path.GetFullPath(savedCustomPath);
-                searchedPaths.Add(fullSavedPath);
-                if (File.Exists(fullSavedPath))
+                if (TryNormalizeSavedDebugPath(savedCustomPath, out var fullSavedPath))
                 {
-                    source = "debug_saved_custom_path";
-                    return fullSavedPath;
+                    searchedPaths.Add(fullSavedPath);
+                    if (File.Exists(fullSavedPath))
+                    {
+                        source = "debug_saved_custom_path";
+                        return fullSavedPath;
+                    }
+
+                    Logger.Warn($"Saved launcher debug host path is invalid; falling back to development paths. Path='{fullSavedPath}'.");
                 }
             }
         }
@@ -229,6 +233,21 @@ internal sealed class DeploymentLocator
         return null;
     }
 
+    private static bool TryNormalizeSavedDebugPath(string savedPath, out string fullSavedPath)
+    {
+        try
+        {
+            fullSavedPath = Path.GetFullPath(savedPath);
+            return true;
+        }
+        catch (Exception ex)
+        {
+            fullSavedPath = string.Empty;
+            Logger.Warn($"Saved launcher debug host path is invalid and cannot be normalized; falling back to development paths. Path='{savedPath}'; Error='{ex.Message}'.");
+            return false;
+        }
+    }
+
     private static string? FindBestDeploymentHost(
         string root,
         string executable,
@@ -303,9 +322,17 @@ internal sealed class DeploymentLocator
         if (Views.ErrorWindow.CheckDevModeEnabled())
         {
             var savedCustomPath = Views.ErrorWindow.GetSavedCustomHostPath();
-            if (!string.IsNullOrWhiteSpace(savedCustomPath) && File.Exists(savedCustomPath))
+            if (!string.IsNullOrWhiteSpace(savedCustomPath))
             {
-                return savedCustomPath;
+                if (TryNormalizeSavedDebugPath(savedCustomPath, out var fullSavedPath) &&
+                    File.Exists(fullSavedPath))
+                {
+                    return fullSavedPath;
+                }
+                else if (!string.IsNullOrWhiteSpace(fullSavedPath))
+                {
+                    Logger.Warn($"Saved launcher debug host path is invalid; falling back to development paths. Path='{fullSavedPath}'.");
+                }
             }
 
             var devPath = ScanDevelopmentPaths(executable);

LanMountainDesktop.Launcher/Services/FlexibleHostLocator.cs

@@ -560,6 +560,11 @@ namespace LanMountainDesktop.Launcher.Services;
             }
         }
 
+        if (string.Equals(source, "saved dev mode path", StringComparison.OrdinalIgnoreCase))
+        {
+            Logger.Warn($"Saved launcher debug host path is invalid; continuing host discovery. Path='{path}'.");
+        }
+
         return null;
     }
 

LanMountainDesktop.Launcher/Services/HostLaunchPlan.cs

@@ -0,0 +1,199 @@
+using LanMountainDesktop.Shared.Contracts.Launcher;
+
+namespace LanMountainDesktop.Launcher.Services;
+
+internal sealed record HostLaunchPlan(
+    string HostPath,
+    string PackageRoot,
+    string WorkingDirectory,
+    IReadOnlyList<string> Arguments,
+    IReadOnlyDictionary<string, string> EnvironmentVariables,
+    AppVersionInfo VersionInfo);
+
+internal static class HostLaunchPlanBuilder
+{
+    private static readonly string[] LauncherOnlyOptions =
+    [
+        "debug", "show-loading-details", "plugins-dir", "source", "result",
+        "app-root",
+        LauncherIpcConstants.LauncherPidEnvVar,
+        LauncherIpcConstants.PackageRootEnvVar,
+        LauncherIpcConstants.VersionEnvVar,
+        LauncherIpcConstants.CodenameEnvVar
+    ];
+
+    public static HostLaunchPlan Build(
+        CommandContext context,
+        DeploymentLocator deploymentLocator,
+        HostResolutionResult resolution)
+    {
+        ArgumentNullException.ThrowIfNull(context);
+        ArgumentNullException.ThrowIfNull(deploymentLocator);
+        ArgumentNullException.ThrowIfNull(resolution);
+
+        if (string.IsNullOrWhiteSpace(resolution.ResolvedHostPath))
+        {
+            throw new InvalidOperationException("Host path must be resolved before building a launch plan.");
+        }
+
+        var hostPath = Path.GetFullPath(resolution.ResolvedHostPath);
+        var packageRoot = ResolvePackageRoot(hostPath, resolution.AppRoot, resolution.ResolutionSource);
+        var versionInfo = deploymentLocator.GetVersionInfo();
+        var arguments = BuildForwardedArguments(context, packageRoot, versionInfo);
+        var environment = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
+        {
+            [LauncherIpcConstants.LauncherPidEnvVar] = Environment.ProcessId.ToString(),
+            [LauncherIpcConstants.PackageRootEnvVar] = packageRoot,
+            [LauncherIpcConstants.VersionEnvVar] = versionInfo.Version,
+            [LauncherIpcConstants.CodenameEnvVar] = versionInfo.Codename
+        };
+
+        return new HostLaunchPlan(
+            hostPath,
+            packageRoot,
+            Directory.Exists(packageRoot)
+                ? packageRoot
+                : Path.GetDirectoryName(hostPath) ?? AppContext.BaseDirectory,
+            arguments,
+            environment,
+            versionInfo);
+    }
+
+    public static string FormatArgumentsForLog(IReadOnlyList<string> arguments)
+    {
+        return string.Join(" ", arguments.Select(QuoteArgument));
+    }
+
+    private static string ResolvePackageRoot(string hostPath, string appRoot, string? resolutionSource)
+    {
+        var fullAppRoot = string.IsNullOrWhiteSpace(appRoot)
+            ? AppContext.BaseDirectory
+            : Path.GetFullPath(appRoot);
+
+        var hostDirectory = Path.GetDirectoryName(hostPath);
+        if (hostDirectory is not null &&
+            Directory.Exists(fullAppRoot) &&
+            IsAppDeploymentDirectory(hostDirectory) &&
+            IsParentOf(fullAppRoot, hostDirectory))
+        {
+            return fullAppRoot;
+        }
+
+        if (string.Equals(resolutionSource, "published_deployment", StringComparison.OrdinalIgnoreCase) ||
+            string.Equals(resolutionSource, "explicit_app_root_deployment", StringComparison.OrdinalIgnoreCase) ||
+            string.Equals(resolutionSource, "legacy_fallback", StringComparison.OrdinalIgnoreCase))
+        {
+            return fullAppRoot;
+        }
+
+        return hostDirectory ?? fullAppRoot;
+    }
+
+    private static IReadOnlyList<string> BuildForwardedArguments(
+        CommandContext context,
+        string packageRoot,
+        AppVersionInfo versionInfo)
+    {
+        var arguments = new List<string>();
+
+        for (var index = 0; index < context.RawArgs.Count; index++)
+        {
+            var arg = context.RawArgs[index];
+
+            if (index == 0 &&
+                !arg.StartsWith("--", StringComparison.Ordinal) &&
+                string.Equals(arg, context.Command, StringComparison.OrdinalIgnoreCase))
+            {
+                continue;
+            }
+
+            if (index == 1 &&
+                !arg.StartsWith("--", StringComparison.Ordinal) &&
+                string.Equals(arg, context.SubCommand, StringComparison.OrdinalIgnoreCase))
+            {
+                continue;
+            }
+
+            if (arg.StartsWith("--", StringComparison.Ordinal))
+            {
+                var key = arg[2..];
+                var equalsIndex = key.IndexOf('=');
+                if (equalsIndex >= 0)
+                {
+                    key = key[..equalsIndex];
+                }
+
+                if (LauncherOnlyOptions.Contains(key, StringComparer.OrdinalIgnoreCase))
+                {
+                    if (equalsIndex < 0 &&
+                        index + 1 < context.RawArgs.Count &&
+                        !context.RawArgs[index + 1].StartsWith("--", StringComparison.Ordinal))
+                    {
+                        index++;
+                    }
+
+                    continue;
+                }
+            }
+
+            arguments.Add(arg);
+        }
+
+        arguments.Add($"--{LauncherIpcConstants.LauncherPidEnvVar}={Environment.ProcessId}");
+        arguments.Add($"--{LauncherIpcConstants.PackageRootEnvVar}={packageRoot}");
+        arguments.Add($"--{LauncherIpcConstants.VersionEnvVar}={versionInfo.Version}");
+        arguments.Add($"--{LauncherIpcConstants.CodenameEnvVar}={versionInfo.Codename}");
+
+        return arguments;
+    }
+
+    private static bool IsAppDeploymentDirectory(string path)
+    {
+        var fileName = Path.GetFileName(Path.TrimEndingDirectorySeparator(path));
+        return fileName.StartsWith("app-", StringComparison.OrdinalIgnoreCase);
+    }
+
+    private static bool IsParentOf(string parent, string child)
+    {
+        var parentPath = Path.GetFullPath(parent).TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
+        var childPath = Path.GetFullPath(child).TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
+        if (string.Equals(parentPath, childPath, StringComparison.OrdinalIgnoreCase))
+        {
+            return true;
+        }
+
+        return childPath.StartsWith(
+            parentPath + Path.DirectorySeparatorChar,
+            OperatingSystem.IsWindows() ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal);
+    }
+
+    private static string QuoteArgument(string value)
+    {
+        if (string.IsNullOrEmpty(value))
+        {
+            return "\"\"";
+        }
+
+        if (!value.Contains('"') && !value.Contains(' ') && !value.Contains('\t'))
+        {
+            return value;
+        }
+
+        var builder = new System.Text.StringBuilder();
+        builder.Append('"');
+        foreach (var ch in value)
+        {
+            if (ch == '"')
+            {
+                builder.Append("\\\"");
+            }
+            else
+            {
+                builder.Append(ch);
+            }
+        }
+
+        builder.Append('"');
+        return builder.ToString();
+    }
+}

LanMountainDesktop.Launcher/Services/Ipc/LauncherCoordinatorIpcClient.cs

@@ -0,0 +1,111 @@
+using System.IO.Pipes;
+using System.Text;
+using System.Text.Json;
+using LanMountainDesktop.Launcher.Models;
+
+namespace LanMountainDesktop.Launcher.Services.Ipc;
+
+internal sealed class LauncherCoordinatorIpcClient
+{
+    private const int LengthPrefixSize = 4;
+    private const int MaxPayloadLength = 1024 * 1024;
+
+    public async Task<LauncherCoordinatorResponse?> SendAsync(
+        string pipeName,
+        LauncherCoordinatorRequest request,
+        TimeSpan timeout)
+    {
+        if (string.IsNullOrWhiteSpace(pipeName))
+        {
+            return null;
+        }
+
+        using var timeoutCts = new CancellationTokenSource(timeout);
+        try
+        {
+            await using var client = new NamedPipeClientStream(
+                ".",
+                pipeName,
+                PipeDirection.InOut,
+                PipeOptions.Asynchronous);
+
+            await client.ConnectAsync(timeoutCts.Token).ConfigureAwait(false);
+            await WriteRequestAsync(client, request, timeoutCts.Token).ConfigureAwait(false);
+            return await ReadResponseAsync(client, timeoutCts.Token).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException)
+        {
+            return null;
+        }
+        catch (TimeoutException)
+        {
+            return null;
+        }
+        catch (Exception ex)
+        {
+            Logger.Warn($"Failed to send launcher coordinator IPC request: {ex.Message}");
+            return null;
+        }
+    }
+
+    private static async Task WriteRequestAsync(
+        Stream stream,
+        LauncherCoordinatorRequest request,
+        CancellationToken cancellationToken)
+    {
+        var json = JsonSerializer.Serialize(request, AppJsonContext.Default.LauncherCoordinatorRequest);
+        var payload = Encoding.UTF8.GetBytes(json);
+        await stream.WriteAsync(BitConverter.GetBytes(payload.Length), cancellationToken).ConfigureAwait(false);
+        await stream.WriteAsync(payload, cancellationToken).ConfigureAwait(false);
+        await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    private static async Task<LauncherCoordinatorResponse?> ReadResponseAsync(
+        Stream stream,
+        CancellationToken cancellationToken)
+    {
+        var lengthBuffer = new byte[LengthPrefixSize];
+        if (!await ReadExactAsync(stream, lengthBuffer, cancellationToken).ConfigureAwait(false))
+        {
+            return null;
+        }
+
+        var payloadLength = BitConverter.ToInt32(lengthBuffer, 0);
+        if (payloadLength <= 0 || payloadLength > MaxPayloadLength)
+        {
+            return null;
+        }
+
+        var payload = new byte[payloadLength];
+        if (!await ReadExactAsync(stream, payload, cancellationToken).ConfigureAwait(false))
+        {
+            return null;
+        }
+
+        return JsonSerializer.Deserialize(
+            Encoding.UTF8.GetString(payload),
+            AppJsonContext.Default.LauncherCoordinatorResponse);
+    }
+
+    private static async Task<bool> ReadExactAsync(
+        Stream stream,
+        byte[] buffer,
+        CancellationToken cancellationToken)
+    {
+        var totalRead = 0;
+        while (totalRead < buffer.Length)
+        {
+            var read = await stream
+                .ReadAsync(buffer.AsMemory(totalRead, buffer.Length - totalRead), cancellationToken)
+                .ConfigureAwait(false);
+            if (read == 0)
+            {
+                return false;
+            }
+
+            totalRead += read;
+        }
+
+        return true;
+    }
+}

LanMountainDesktop.Launcher/Services/Ipc/LauncherCoordinatorIpcServer.cs

@@ -0,0 +1,235 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using System.IO.Pipes;
+using LanMountainDesktop.Launcher.Models;
+
+namespace LanMountainDesktop.Launcher.Services.Ipc;
+
+internal sealed class LauncherCoordinatorIpcServer : IDisposable
+{
+    private const int LengthPrefixSize = 4;
+    private const int MaxPayloadLength = 1024 * 1024;
+    private readonly string _pipeName;
+    private readonly Func<LauncherCoordinatorRequest, LauncherCoordinatorStatus, Task<LauncherCoordinatorResponse>> _requestHandler;
+    private readonly Action<LauncherCoordinatorStatus> _heartbeatHandler;
+    private readonly CancellationTokenSource _cts = new();
+    private readonly object _statusGate = new();
+    private LauncherCoordinatorStatus _status;
+    private Task? _listenTask;
+    private Task? _heartbeatTask;
+
+    public LauncherCoordinatorIpcServer(
+        string pipeName,
+        LauncherCoordinatorStatus initialStatus,
+        Func<LauncherCoordinatorRequest, LauncherCoordinatorStatus, Task<LauncherCoordinatorResponse>> requestHandler,
+        Action<LauncherCoordinatorStatus> heartbeatHandler)
+    {
+        _pipeName = pipeName;
+        _status = initialStatus;
+        _requestHandler = requestHandler;
+        _heartbeatHandler = heartbeatHandler;
+    }
+
+    public static string CreatePipeName()
+    {
+        var seed = $"{Environment.UserName}:{Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)}";
+        var bytes = SHA256.HashData(Encoding.UTF8.GetBytes(seed.ToLowerInvariant()));
+        return $"LanMountainDesktop_Launcher_Coordinator_{Convert.ToHexString(bytes[..8])}";
+    }
+
+    public void Start()
+    {
+        _listenTask ??= Task.Run(ListenLoopAsync);
+        _heartbeatTask ??= Task.Run(HeartbeatLoopAsync);
+    }
+
+    public LauncherCoordinatorStatus GetStatus()
+    {
+        lock (_statusGate)
+        {
+            return _status;
+        }
+    }
+
+    public void UpdateStatus(LauncherCoordinatorStatus status)
+    {
+        lock (_statusGate)
+        {
+            _status = status;
+        }
+    }
+
+    public void Dispose()
+    {
+        _cts.Cancel();
+
+        try
+        {
+            _listenTask?.Wait(TimeSpan.FromSeconds(1));
+            _heartbeatTask?.Wait(TimeSpan.FromSeconds(1));
+        }
+        catch
+        {
+        }
+
+        _cts.Dispose();
+    }
+
+    private async Task ListenLoopAsync()
+    {
+        while (!_cts.IsCancellationRequested)
+        {
+            NamedPipeServerStream? server = null;
+            try
+            {
+                server = new NamedPipeServerStream(
+                    _pipeName,
+                    PipeDirection.InOut,
+                    8,
+                    PipeTransmissionMode.Byte,
+                    PipeOptions.Asynchronous);
+
+                await server.WaitForConnectionAsync(_cts.Token).ConfigureAwait(false);
+                var connectedServer = server;
+                _ = Task.Run(() => HandleConnectionAsync(connectedServer, _cts.Token), _cts.Token);
+                server = null;
+            }
+            catch (OperationCanceledException)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                Logger.Warn($"Launcher coordinator IPC listener failed: {ex.Message}");
+                try
+                {
+                    await Task.Delay(250, _cts.Token).ConfigureAwait(false);
+                }
+                catch (OperationCanceledException)
+                {
+                    break;
+                }
+            }
+            finally
+            {
+                server?.Dispose();
+            }
+        }
+    }
+
+    private async Task HeartbeatLoopAsync()
+    {
+        while (!_cts.IsCancellationRequested)
+        {
+            try
+            {
+                _heartbeatHandler(GetStatus());
+                await Task.Delay(TimeSpan.FromSeconds(2), _cts.Token).ConfigureAwait(false);
+            }
+            catch (OperationCanceledException)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                Logger.Warn($"Launcher coordinator heartbeat failed: {ex.Message}");
+            }
+        }
+    }
+
+    private async Task HandleConnectionAsync(NamedPipeServerStream server, CancellationToken cancellationToken)
+    {
+        try
+        {
+            var request = await ReadRequestAsync(server, cancellationToken).ConfigureAwait(false);
+            var status = GetStatus();
+            var response = request is null
+                ? new LauncherCoordinatorResponse
+                {
+                    Accepted = false,
+                    Code = "invalid_request",
+                    Message = "Launcher coordinator request was invalid.",
+                    Status = status
+                }
+                : await _requestHandler(request, status).ConfigureAwait(false);
+
+            await WriteResponseAsync(server, response, cancellationToken).ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            Logger.Warn($"Launcher coordinator IPC request failed: {ex.Message}");
+        }
+        finally
+        {
+            try
+            {
+                server.Dispose();
+            }
+            catch
+            {
+            }
+        }
+    }
+
+    private static async Task<LauncherCoordinatorRequest?> ReadRequestAsync(
+        Stream stream,
+        CancellationToken cancellationToken)
+    {
+        var lengthBuffer = new byte[LengthPrefixSize];
+        if (!await ReadExactAsync(stream, lengthBuffer, cancellationToken).ConfigureAwait(false))
+        {
+            return null;
+        }
+
+        var payloadLength = BitConverter.ToInt32(lengthBuffer, 0);
+        if (payloadLength <= 0 || payloadLength > MaxPayloadLength)
+        {
+            return null;
+        }
+
+        var payload = new byte[payloadLength];
+        if (!await ReadExactAsync(stream, payload, cancellationToken).ConfigureAwait(false))
+        {
+            return null;
+        }
+
+        return JsonSerializer.Deserialize(
+            Encoding.UTF8.GetString(payload),
+            AppJsonContext.Default.LauncherCoordinatorRequest);
+    }
+
+    private static async Task WriteResponseAsync(
+        Stream stream,
+        LauncherCoordinatorResponse response,
+        CancellationToken cancellationToken)
+    {
+        var json = JsonSerializer.Serialize(response, AppJsonContext.Default.LauncherCoordinatorResponse);
+        var payload = Encoding.UTF8.GetBytes(json);
+        await stream.WriteAsync(BitConverter.GetBytes(payload.Length), cancellationToken).ConfigureAwait(false);
+        await stream.WriteAsync(payload, cancellationToken).ConfigureAwait(false);
+        await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    private static async Task<bool> ReadExactAsync(
+        Stream stream,
+        byte[] buffer,
+        CancellationToken cancellationToken)
+    {
+        var totalRead = 0;
+        while (totalRead < buffer.Length)
+        {
+            var read = await stream
+                .ReadAsync(buffer.AsMemory(totalRead, buffer.Length - totalRead), cancellationToken)
+                .ConfigureAwait(false);
+            if (read == 0)
+            {
+                return false;
+            }
+
+            totalRead += read;
+        }
+
+        return true;
+    }
+}

LanMountainDesktop.Launcher/Services/LauncherDebugSettingsStore.cs

@@ -0,0 +1,124 @@
+namespace LanMountainDesktop.Launcher.Services;
+
+internal sealed record LauncherDebugSettings(bool DevModeEnabled, string? CustomHostPath);
+
+internal static class LauncherDebugSettingsStore
+{
+    private const string DevModeFileName = "dev-mode.flag";
+    private const string CustomHostPathFileName = "custom-host-path.txt";
+    private const string LegacyDevModeFileName = "devmode.config";
+    private const string LegacyCustomHostPathFileName = "custom-host-path.config";
+
+    internal static string? ConfigBaseDirectoryOverride { get; set; }
+
+    public static string ConfigBaseDirectory => ConfigBaseDirectoryOverride ?? ResolveConfigBaseDirectory();
+
+    public static LauncherDebugSettings Load()
+    {
+        return new LauncherDebugSettings(
+            LoadDevModeState(),
+            LoadCustomHostPath());
+    }
+
+    public static bool IsDevModeEnabled() => Load().DevModeEnabled;
+
+    public static string? GetSavedCustomHostPath() => Load().CustomHostPath;
+
+    public static void Save(LauncherDebugSettings settings)
+    {
+        try
+        {
+            Directory.CreateDirectory(ConfigBaseDirectory);
+            File.WriteAllText(GetPath(DevModeFileName), settings.DevModeEnabled.ToString());
+            File.WriteAllText(GetPath(CustomHostPathFileName), settings.CustomHostPath ?? string.Empty);
+        }
+        catch (Exception ex)
+        {
+            Logger.Warn($"Failed to save launcher debug settings: {ex.Message}");
+        }
+    }
+
+    public static void SaveDevModeState(bool enabled)
+    {
+        var current = Load();
+        Save(current with { DevModeEnabled = enabled });
+    }
+
+    public static void SaveCustomHostPath(string? customHostPath)
+    {
+        var current = Load();
+        Save(current with { CustomHostPath = customHostPath });
+    }
+
+    private static bool LoadDevModeState()
+    {
+        var newValue = TryReadText(GetPath(DevModeFileName));
+        if (!string.IsNullOrWhiteSpace(newValue))
+        {
+            return TryParseDevMode(newValue);
+        }
+
+        var legacyValue = TryReadText(GetPath(LegacyDevModeFileName));
+        return !string.IsNullOrWhiteSpace(legacyValue) && TryParseDevMode(legacyValue);
+    }
+
+    private static string? LoadCustomHostPath()
+    {
+        var newValue = TryReadText(GetPath(CustomHostPathFileName));
+        if (!string.IsNullOrWhiteSpace(newValue))
+        {
+            return newValue.Trim();
+        }
+
+        var legacyValue = TryReadText(GetPath(LegacyCustomHostPathFileName));
+        return string.IsNullOrWhiteSpace(legacyValue) ? null : legacyValue.Trim();
+    }
+
+    private static bool TryParseDevMode(string value)
+    {
+        var normalized = value.Trim();
+        return normalized == "1" ||
+               normalized.Equals("true", StringComparison.OrdinalIgnoreCase) ||
+               normalized.Equals("yes", StringComparison.OrdinalIgnoreCase) ||
+               normalized.Equals("on", StringComparison.OrdinalIgnoreCase);
+    }
+
+    private static string? TryReadText(string path)
+    {
+        try
+        {
+            return File.Exists(path) ? File.ReadAllText(path) : null;
+        }
+        catch (Exception ex)
+        {
+            Logger.Warn($"Failed to read launcher debug setting '{path}': {ex.Message}");
+            return null;
+        }
+    }
+
+    private static string GetPath(string fileName) => Path.Combine(ConfigBaseDirectory, fileName);
+
+    private static string ResolveConfigBaseDirectory()
+    {
+        try
+        {
+            var appData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+            if (!string.IsNullOrWhiteSpace(appData))
+            {
+                return Path.Combine(appData, "LanMountainDesktop", ".launcher");
+            }
+        }
+        catch
+        {
+        }
+
+        try
+        {
+            return Path.Combine(AppContext.BaseDirectory, ".launcher");
+        }
+        catch
+        {
+            return Path.Combine(Directory.GetCurrentDirectory(), ".launcher");
+        }
+    }
+}

LanMountainDesktop.Launcher/Services/StartupAttemptRegistry.cs

@@ -0,0 +1,540 @@
+using System.Diagnostics;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using LanMountainDesktop.Launcher.Models;
+using LanMountainDesktop.Shared.Contracts.Launcher;
+
+namespace LanMountainDesktop.Launcher.Services;
+
+internal sealed class StartupAttemptRegistry
+{
+    private static readonly TimeSpan CoordinatorHeartbeatTimeout = TimeSpan.FromSeconds(10);
+    private static readonly JsonSerializerOptions SerializerOptions = new()
+    {
+        WriteIndented = true
+    };
+
+    private readonly string _statePath;
+    private readonly string _mutexName;
+    private string? _ownedAttemptId;
+
+    public StartupAttemptRegistry()
+        : this(Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
+            "LanMountainDesktop",
+            ".launcher",
+            "state",
+            "startup-attempt.json"))
+    {
+    }
+
+    internal StartupAttemptRegistry(string statePath)
+    {
+        _statePath = statePath;
+        _mutexName = $"LanMountainDesktop.Launcher.StartupAttempt.{ComputePathHash(statePath)}";
+    }
+
+    public StartupAttemptRecord StartOwnedAttempt(
+        int hostPid,
+        string launchSource,
+        string successPolicy,
+        StartupStage stage,
+        string? message)
+    {
+        var record = new StartupAttemptRecord
+        {
+            AttemptId = Guid.NewGuid().ToString("N"),
+            HostPid = hostPid,
+            CoordinatorPid = Environment.ProcessId,
+            LaunchSource = launchSource,
+            SuccessPolicy = successPolicy,
+            LastObservedStage = stage,
+            LastObservedMessage = message ?? string.Empty,
+            StartedAtUtc = DateTimeOffset.UtcNow,
+            UpdatedAtUtc = DateTimeOffset.UtcNow,
+            HeartbeatAtUtc = DateTimeOffset.UtcNow,
+            State = StartupAttemptState.Pending
+        };
+
+        ExecuteWithLock(() =>
+        {
+            SaveUnsafe(record);
+            _ownedAttemptId = record.AttemptId;
+        });
+
+        return Clone(record);
+    }
+
+    public bool TryReserveCoordinator(
+        string launchSource,
+        string successPolicy,
+        string coordinatorPipeName,
+        out StartupAttemptRecord reservedAttempt,
+        out StartupAttemptRecord? activeCoordinatorAttempt)
+    {
+        StartupAttemptRecord? reserved = null;
+        StartupAttemptRecord? active = null;
+
+        ExecuteWithLock(() =>
+        {
+            var existing = LoadUnsafe();
+            if (existing is not null && IsCoordinatorLive(existing))
+            {
+                active = Clone(existing);
+                return;
+            }
+
+            if (existing is not null && IsRecoverableCoordinatorAttempt(existing))
+            {
+                existing.CoordinatorPid = Environment.ProcessId;
+                existing.CoordinatorPipeName = coordinatorPipeName;
+                existing.HeartbeatAtUtc = DateTimeOffset.UtcNow;
+                existing.UpdatedAtUtc = DateTimeOffset.UtcNow;
+                if (existing.HostPid <= 0)
+                {
+                    existing.ReservedBeforeHostStart = true;
+                }
+
+                if (existing.State == StartupAttemptState.DetachedWaiting)
+                {
+                    existing.State = StartupAttemptState.SoftTimeout;
+                }
+
+                _ownedAttemptId = existing.AttemptId;
+                SaveUnsafe(existing);
+                reserved = Clone(existing);
+                return;
+            }
+
+            var now = DateTimeOffset.UtcNow;
+            var record = new StartupAttemptRecord
+            {
+                AttemptId = Guid.NewGuid().ToString("N"),
+                HostPid = 0,
+                CoordinatorPid = Environment.ProcessId,
+                CoordinatorPipeName = coordinatorPipeName,
+                LaunchSource = launchSource,
+                SuccessPolicy = successPolicy,
+                LastObservedStage = StartupStage.Initializing,
+                LastObservedMessage = "Launcher coordinator reserved startup ownership.",
+                StartedAtUtc = now,
+                UpdatedAtUtc = now,
+                HeartbeatAtUtc = now,
+                ReservedBeforeHostStart = true,
+                State = StartupAttemptState.Pending
+            };
+
+            _ownedAttemptId = record.AttemptId;
+            SaveUnsafe(record);
+            reserved = Clone(record);
+        });
+
+        reservedAttempt = reserved ?? new StartupAttemptRecord();
+        activeCoordinatorAttempt = active;
+        return reserved is not null;
+    }
+
+    public StartupAttemptRecord? GetOwnedAttempt()
+    {
+        StartupAttemptRecord? result = null;
+        if (string.IsNullOrWhiteSpace(_ownedAttemptId))
+        {
+            return null;
+        }
+
+        ExecuteWithLock(() =>
+        {
+            var record = LoadUnsafe();
+            if (record is not null && string.Equals(record.AttemptId, _ownedAttemptId, StringComparison.Ordinal))
+            {
+                result = Clone(record);
+            }
+        });
+
+        return result;
+    }
+
+    public StartupAttemptRecord? TryGetLiveCoordinatorAttempt()
+    {
+        StartupAttemptRecord? result = null;
+        ExecuteWithLock(() =>
+        {
+            var record = LoadUnsafe();
+            if (record is not null && IsCoordinatorLive(record))
+            {
+                result = Clone(record);
+            }
+        });
+
+        return result;
+    }
+
+    public StartupAttemptRecord? TryGetLatestAttempt()
+    {
+        StartupAttemptRecord? result = null;
+        ExecuteWithLock(() =>
+        {
+            var record = LoadUnsafe();
+            if (record is not null)
+            {
+                result = Clone(record);
+            }
+        });
+
+        return result;
+    }
+
+    public StartupAttemptRecord AssignOwnedHostProcess(
+        int hostPid,
+        StartupStage stage,
+        string? message)
+    {
+        StartupAttemptRecord? result = null;
+        UpdateOwned(record =>
+        {
+            record.HostPid = hostPid;
+            record.LastObservedStage = stage;
+            record.LastObservedMessage = message ?? record.LastObservedMessage;
+            record.ReservedBeforeHostStart = false;
+            result = Clone(record);
+        });
+
+        return result ?? StartOwnedAttempt(
+            hostPid,
+            string.Empty,
+            string.Empty,
+            stage,
+            message);
+    }
+
+    public bool AdoptAttempt(string attemptId)
+    {
+        if (string.IsNullOrWhiteSpace(attemptId))
+        {
+            return false;
+        }
+
+        var adopted = false;
+        ExecuteWithLock(() =>
+        {
+            var record = LoadUnsafe();
+            if (record is null || !string.Equals(record.AttemptId, attemptId, StringComparison.Ordinal))
+            {
+                return;
+            }
+
+            if (!IsAttachable(record))
+            {
+                return;
+            }
+
+            _ownedAttemptId = record.AttemptId;
+            if (record.State == StartupAttemptState.DetachedWaiting)
+            {
+                record.State = StartupAttemptState.SoftTimeout;
+            }
+
+            record.UpdatedAtUtc = DateTimeOffset.UtcNow;
+            SaveUnsafe(record);
+            adopted = true;
+        });
+
+        return adopted;
+    }
+
+    public StartupAttemptRecord? TryGetAttachableAttempt(string launchSource, string successPolicy)
+    {
+        StartupAttemptRecord? result = null;
+        ExecuteWithLock(() =>
+        {
+            var record = LoadUnsafe();
+            if (record is null ||
+                !IsAttachable(record) ||
+                !string.Equals(record.LaunchSource, launchSource, StringComparison.OrdinalIgnoreCase) ||
+                !string.Equals(record.SuccessPolicy, successPolicy, StringComparison.OrdinalIgnoreCase))
+            {
+                return;
+            }
+
+            result = Clone(record);
+        });
+
+        return result;
+    }
+
+    public void MarkOwnedIpcConnected()
+    {
+        UpdateOwned(record =>
+        {
+            record.IpcConnected = true;
+            record.PublicIpcConnected = true;
+        });
+    }
+
+    public void UpdateOwnedStage(StartupStage stage, string? message, bool ipcConnected)
+    {
+        UpdateOwned(record =>
+        {
+            record.LastObservedStage = stage;
+            record.LastObservedMessage = message ?? string.Empty;
+            if (ipcConnected)
+            {
+                record.IpcConnected = true;
+                record.PublicIpcConnected = true;
+            }
+        });
+    }
+
+    public void UpdateOwnedCoordinatorHeartbeat(LauncherCoordinatorStatus status)
+    {
+        UpdateOwned(record =>
+        {
+            record.CoordinatorPid = Environment.ProcessId;
+            record.HeartbeatAtUtc = DateTimeOffset.UtcNow;
+            record.LastObservedStage = status.LastObservedStage;
+            record.LastObservedMessage = status.LastObservedMessage;
+            record.IpcConnected = status.PublicIpcConnected;
+            record.PublicIpcConnected = status.PublicIpcConnected;
+            record.ShellStatus = status.ShellStatus?.ShellState ?? status.State;
+        });
+    }
+
+    public void MarkOwnedSoftTimeout(string? message)
+    {
+        UpdateOwned(record =>
+        {
+            record.State = StartupAttemptState.SoftTimeout;
+            record.LastObservedMessage = message ?? record.LastObservedMessage;
+        });
+    }
+
+    public void MarkOwnedWaitingForShell(string? message)
+    {
+        UpdateOwned(record =>
+        {
+            if (record.State is StartupAttemptState.Pending or StartupAttemptState.SoftTimeout or StartupAttemptState.DetachedWaiting)
+            {
+                record.State = StartupAttemptState.WaitingForShell;
+            }
+
+            record.LastObservedMessage = message ?? record.LastObservedMessage;
+        });
+    }
+
+    public void MarkOwnedDetachedWaiting()
+    {
+        UpdateOwned(record =>
+        {
+            if (record.State is StartupAttemptState.Pending or StartupAttemptState.SoftTimeout)
+            {
+                record.State = StartupAttemptState.DetachedWaiting;
+            }
+        });
+    }
+
+    public void MarkOwnedSucceeded(StartupStage stage, string? message)
+    {
+        UpdateOwned(record =>
+        {
+            record.State = StartupAttemptState.Succeeded;
+            record.LastObservedStage = stage;
+            record.LastObservedMessage = message ?? record.LastObservedMessage;
+        });
+    }
+
+    public void MarkOwnedFailed(StartupStage stage, string? message)
+    {
+        UpdateOwned(record =>
+        {
+            record.State = StartupAttemptState.Failed;
+            record.LastObservedStage = stage;
+            record.LastObservedMessage = message ?? record.LastObservedMessage;
+        });
+    }
+
+    private void UpdateOwned(Action<StartupAttemptRecord> update)
+    {
+        if (string.IsNullOrWhiteSpace(_ownedAttemptId))
+        {
+            return;
+        }
+
+        ExecuteWithLock(() =>
+        {
+            var record = LoadUnsafe();
+            if (record is null || !string.Equals(record.AttemptId, _ownedAttemptId, StringComparison.Ordinal))
+            {
+                return;
+            }
+
+            update(record);
+            record.UpdatedAtUtc = DateTimeOffset.UtcNow;
+            SaveUnsafe(record);
+        });
+    }
+
+    private void ExecuteWithLock(Action action)
+    {
+        using var mutex = new Mutex(false, _mutexName);
+        var hasHandle = false;
+        try
+        {
+            try
+            {
+                hasHandle = mutex.WaitOne(TimeSpan.FromSeconds(2));
+            }
+            catch (AbandonedMutexException)
+            {
+                hasHandle = true;
+            }
+
+            if (!hasHandle)
+            {
+                return;
+            }
+
+            action();
+        }
+        finally
+        {
+            if (hasHandle)
+            {
+                mutex.ReleaseMutex();
+            }
+        }
+    }
+
+    private StartupAttemptRecord? LoadUnsafe()
+    {
+        if (!File.Exists(_statePath))
+        {
+            return null;
+        }
+
+        try
+        {
+            var json = File.ReadAllText(_statePath);
+            return JsonSerializer.Deserialize<StartupAttemptRecord>(json, SerializerOptions);
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    private void SaveUnsafe(StartupAttemptRecord record)
+    {
+        var directory = Path.GetDirectoryName(_statePath);
+        if (!string.IsNullOrWhiteSpace(directory))
+        {
+            Directory.CreateDirectory(directory);
+        }
+
+        File.WriteAllText(_statePath, JsonSerializer.Serialize(record, SerializerOptions));
+    }
+
+    private static bool IsAttachable(StartupAttemptRecord record)
+    {
+        if (record.State is not (
+            StartupAttemptState.Pending or
+            StartupAttemptState.SoftTimeout or
+            StartupAttemptState.DetachedWaiting or
+            StartupAttemptState.WaitingForShell))
+        {
+            return false;
+        }
+
+        return TryGetLiveProcess(record.HostPid, out _);
+    }
+
+    private static bool IsRecoverableCoordinatorAttempt(StartupAttemptRecord record)
+    {
+        if (record.State is not (
+            StartupAttemptState.Pending or
+            StartupAttemptState.SoftTimeout or
+            StartupAttemptState.DetachedWaiting or
+            StartupAttemptState.WaitingForShell))
+        {
+            return false;
+        }
+
+        if (record.HostPid <= 0)
+        {
+            return true;
+        }
+
+        return TryGetLiveProcess(record.HostPid, out _);
+    }
+
+    private static bool IsCoordinatorLive(StartupAttemptRecord record)
+    {
+        if (record.State is not (
+            StartupAttemptState.Pending or
+            StartupAttemptState.SoftTimeout or
+            StartupAttemptState.DetachedWaiting or
+            StartupAttemptState.WaitingForShell))
+        {
+            return false;
+        }
+
+        if (record.CoordinatorPid <= 0 ||
+            string.IsNullOrWhiteSpace(record.CoordinatorPipeName) ||
+            DateTimeOffset.UtcNow - record.HeartbeatAtUtc > CoordinatorHeartbeatTimeout)
+        {
+            return false;
+        }
+
+        return TryGetLiveProcess(record.CoordinatorPid, out _);
+    }
+
+    private static bool TryGetLiveProcess(int processId, out Process? process)
+    {
+        process = null;
+        if (processId <= 0)
+        {
+            return false;
+        }
+
+        try
+        {
+            process = Process.GetProcessById(processId);
+            return !process.HasExited;
+        }
+        catch
+        {
+            process?.Dispose();
+            process = null;
+            return false;
+        }
+    }
+
+    private static string ComputePathHash(string statePath)
+    {
+        var bytes = SHA256.HashData(Encoding.UTF8.GetBytes(statePath.ToLowerInvariant()));
+        return Convert.ToHexString(bytes[..8]);
+    }
+
+    private static StartupAttemptRecord Clone(StartupAttemptRecord record)
+    {
+        return new StartupAttemptRecord
+        {
+            AttemptId = record.AttemptId,
+            HostPid = record.HostPid,
+            CoordinatorPid = record.CoordinatorPid,
+            CoordinatorPipeName = record.CoordinatorPipeName,
+            StartedAtUtc = record.StartedAtUtc,
+            UpdatedAtUtc = record.UpdatedAtUtc,
+            HeartbeatAtUtc = record.HeartbeatAtUtc,
+            LaunchSource = record.LaunchSource,
+            SuccessPolicy = record.SuccessPolicy,
+            LastObservedStage = record.LastObservedStage,
+            LastObservedMessage = record.LastObservedMessage,
+            IpcConnected = record.IpcConnected,
+            PublicIpcConnected = record.PublicIpcConnected,
+            ShellStatus = record.ShellStatus,
+            ReservedBeforeHostStart = record.ReservedBeforeHostStart,
+            State = record.State
+        };
+    }
+}

LanMountainDesktop.Launcher/Views/ErrorDebugWindow.axaml.cs

@@ -5,52 +5,41 @@ using Avalonia.Platform.Storage;
 
 namespace LanMountainDesktop.Launcher.Views;
 
-/// <summary>
-/// 错误调试窗口 - 开发人员专用调试设置
-/// </summary>
 public partial class ErrorDebugWindow : Window
 {
     private string? _selectedHostPath;
-    private bool _isInitialized = false;
+    private bool _isInitialized;
 
-    /// <summary>
-    /// 是否启用了开发模式
-    /// </summary>
     public bool IsDevModeEnabled { get; private set; }
 
-    /// <summary>
-    /// 选择的主程序路径
-    /// </summary>
+    public bool WasAccepted { get; private set; }
+
     public string? SelectedHostPath => _selectedHostPath;
 
     public ErrorDebugWindow()
     {
         AvaloniaXamlLoader.Load(this);
-        
-        // 延迟到窗口加载完成后再初始化组件
-        this.Loaded += OnWindowLoaded;
+        Loaded += OnWindowLoaded;
     }
 
-    public ErrorDebugWindow(bool devModeEnabled, string? initialPath) : this()
+    public ErrorDebugWindow(bool devModeEnabled, string? initialPath)
+        : this()
     {
         IsDevModeEnabled = devModeEnabled;
         _selectedHostPath = initialPath;
     }
 
-    /// <summary>
-    /// 窗口加载完成事件
-    /// </summary>
     private void OnWindowLoaded(object? sender, RoutedEventArgs e)
     {
-        if (_isInitialized) return;
+        if (_isInitialized)
+        {
+            return;
+        }
+
         _isInitialized = true;
-        
-        Console.WriteLine("[ErrorDebugWindow] Window loaded, initializing components...");
         InitializeComponents();
-        
-        // 设置初始值（在视觉树准备好后）
-        var devModeToggle = this.FindControl<ToggleSwitch>("DevModeToggle");
-        if (devModeToggle is not null)
+
+        if (this.FindControl<ToggleSwitch>("DevModeToggle") is { } devModeToggle)
         {
             devModeToggle.IsChecked = IsDevModeEnabled;
         }
@@ -60,113 +49,72 @@ public partial class ErrorDebugWindow : Window
 
     private void InitializeComponents()
     {
-        // 开发模式开关
-        var devModeToggle = this.FindControl<ToggleSwitch>("DevModeToggle");
-        if (devModeToggle is not null)
+        if (this.FindControl<ToggleSwitch>("DevModeToggle") is { } devModeToggle)
         {
-            devModeToggle.IsCheckedChanged += (s, e) =>
+            devModeToggle.IsCheckedChanged += (_, _) =>
             {
                 IsDevModeEnabled = devModeToggle.IsChecked ?? false;
-                Console.WriteLine($"[ErrorDebugWindow] DevMode changed to: {IsDevModeEnabled}");
             };
-            Console.WriteLine("[ErrorDebugWindow] DevModeToggle event bound");
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorDebugWindow] Failed to find DevModeToggle!");
         }
 
-        // 浏览按钮
-        var browseButton = this.FindControl<Button>("BrowseButton");
-        if (browseButton is not null)
+        if (this.FindControl<Button>("BrowseButton") is { } browseButton)
         {
             browseButton.Click += OnBrowseClick;
-            Console.WriteLine("[ErrorDebugWindow] BrowseButton event bound");
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorDebugWindow] Failed to find BrowseButton!");
         }
 
-        // 确定按钮
-        var okButton = this.FindControl<Button>("OkButton");
-        if (okButton is not null)
+        if (this.FindControl<Button>("OkButton") is { } okButton)
         {
-            okButton.Click += (s, e) => Close();
-            Console.WriteLine("[ErrorDebugWindow] OkButton event bound");
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorDebugWindow] Failed to find OkButton!");
-        }
-
-        // 取消按钮
-        var cancelButton = this.FindControl<Button>("CancelButton");
-        if (cancelButton is not null)
-        {
-            cancelButton.Click += (s, e) =>
+            okButton.Click += (_, _) =>
             {
-                // 取消时恢复原始状态
-                IsDevModeEnabled = false;
-                _selectedHostPath = null;
-                Console.WriteLine("[ErrorDebugWindow] Cancel clicked, resetting state");
+                WasAccepted = true;
                 Close();
             };
-            Console.WriteLine("[ErrorDebugWindow] CancelButton event bound");
         }
-        else
+
+        if (this.FindControl<Button>("CancelButton") is { } cancelButton)
         {
-            Console.Error.WriteLine("[ErrorDebugWindow] Failed to find CancelButton!");
+            cancelButton.Click += (_, _) => Close();
         }
-        
-        Console.WriteLine("[ErrorDebugWindow] Components initialization completed");
     }
 
-    /// <summary>
-    /// 浏览按钮点击
-    /// </summary>
     private async void OnBrowseClick(object? sender, RoutedEventArgs e)
     {
         var storageProvider = StorageProvider;
-        if (storageProvider is null) return;
+        if (storageProvider is null)
+        {
+            return;
+        }
 
         var options = new FilePickerOpenOptions
         {
-            Title = "选择阑山桌面主程序",
+            Title = "Select LanMountainDesktop host executable",
             AllowMultiple = false,
-            FileTypeFilter = new[]
-            {
-                new FilePickerFileType("可执行文件")
+            FileTypeFilter =
+            [
+                new FilePickerFileType("Executable")
                 {
                     Patterns = OperatingSystem.IsWindows()
-                        ? new[] { "*.exe" }
-                        : new[] { "*" }
+                        ? ["*.exe"]
+                        : ["*"]
                 }
-            }
+            ]
         };
 
         var result = await storageProvider.OpenFilePickerAsync(options);
-        if (result.Count > 0)
+        if (result.Count <= 0)
         {
-            _selectedHostPath = result[0].Path.LocalPath;
-            Console.WriteLine($"[ErrorDebugWindow] Selected host path: {_selectedHostPath}");
-            UpdatePathDisplay(_selectedHostPath);
+            return;
         }
+
+        _selectedHostPath = result[0].Path.LocalPath;
+        UpdatePathDisplay(_selectedHostPath);
     }
 
-    /// <summary>
-    /// 更新路径显示
-    /// </summary>
     private void UpdatePathDisplay(string? path)
     {
-        var pathTextBlock = this.FindControl<TextBlock>("PathTextBlock");
-        if (pathTextBlock is not null)
+        if (this.FindControl<TextBlock>("PathTextBlock") is { } pathTextBlock)
         {
-            pathTextBlock.Text = string.IsNullOrEmpty(path) ? "未选择" : path;
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorDebugWindow] Failed to find PathTextBlock!");
+            pathTextBlock.Text = string.IsNullOrEmpty(path) ? "Not selected" : path;
         }
     }
 }

LanMountainDesktop.Launcher/Views/ErrorWindow.axaml

@@ -3,102 +3,96 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:views="clr-namespace:LanMountainDesktop.Launcher.Views"
-        xmlns:ui="using:FluentAvalonia.UI.Controls"
         mc:Ignorable="d"
-        d:DesignWidth="520"
-        d:DesignHeight="280"
         x:Class="LanMountainDesktop.Launcher.Views.ErrorWindow"
         x:DataType="views:ErrorWindow"
-        Title="阑山桌面"
-        Width="520"
-        Height="280"
+        Title="LanMountain Desktop"
+        Width="560"
+        Height="320"
         CanResize="False"
         WindowStartupLocation="CenterScreen"
-        Background="{DynamicResource SolidBackgroundFillColorBaseBrush}"
+        Background="#111318"
         TransparencyLevelHint="None"
         Icon="/Assets/logo.ico">
   <Design.DataContext>
     <views:ErrorWindow />
   </Design.DataContext>
 
-  <!-- Fluent Design 风格对话框布局 -->
   <Grid RowDefinitions="*,Auto">
-    <!-- 主内容区域：左侧图标 + 右侧文字 -->
-    <Grid Grid.Row="0" Margin="24,24,24,16" ColumnDefinitions="Auto,*">
-      
-      <!-- 左侧：错误图标（可点击进入调试模式） -->
+    <Grid Grid.Row="0"
+          Margin="24"
+          ColumnDefinitions="Auto,*">
       <Border x:Name="ErrorIconBorder"
               Grid.Column="0"
-              Width="48"
-              Height="48"
-              Margin="0,4,16,0"
-              Background="{DynamicResource SystemFillColorCriticalBackgroundBrush}"
-              CornerRadius="24"
+              Width="52"
+              Height="52"
+              Margin="0,4,18,0"
+              Background="#2B161A"
+              CornerRadius="26"
               VerticalAlignment="Top">
-        <TextBlock Text="&#xEA39;"
+        <TextBlock Text="!"
                    FontSize="24"
-                   FontFamily="{DynamicResource SymbolThemeFontFamily}"
-                   Foreground="{DynamicResource SystemFillColorCriticalBrush}"
+                   FontWeight="Bold"
+                   Foreground="#FFB4AB"
                    HorizontalAlignment="Center"
-                   VerticalAlignment="Center"/>
+                   VerticalAlignment="Center" />
       </Border>
-      
-      <!-- 右侧：标题 + 内容 -->
-      <StackPanel Grid.Column="1" Spacing="8">
-        <!-- 标题 -->
+
+      <StackPanel Grid.Column="1"
+                  Spacing="10">
         <TextBlock x:Name="TitleText"
-                   Text="启动失败"
-                   FontSize="18"
+                   Text="Launcher could not confirm startup"
+                   FontSize="20"
                    FontWeight="SemiBold"
-                   Foreground="{DynamicResource TextFillColorPrimaryBrush}"
-                   TextWrapping="Wrap"/>
-        
-        <!-- 错误信息 -->
+                   Foreground="#F6F7FB"
+                   TextWrapping="Wrap" />
+
         <TextBlock x:Name="ErrorMessageText"
-                   Text="找不到阑山桌面应用程序。"
+                   Text="LanMountain Desktop did not reach the expected startup state."
                    FontSize="14"
-                   Foreground="{DynamicResource TextFillColorSecondaryBrush}"
+                   Foreground="#D2D7E1"
                    TextWrapping="Wrap"
-                   LineHeight="20"/>
-        
-        <!-- 建议信息 -->
+                   LineHeight="22" />
+
         <TextBlock x:Name="SuggestionText"
-                   Text="请确保应用程序已正确安装，或尝试重新安装。"
+                   Text="You can inspect logs, retry when the old process is gone, or reactivate the current instance."
                    FontSize="13"
-                   Foreground="{DynamicResource TextFillColorTertiaryBrush}"
+                   Foreground="#9BA5B7"
                    TextWrapping="Wrap"
-                   LineHeight="18"
-                   Margin="0,4,0,0"/>
+                   LineHeight="20" />
       </StackPanel>
     </Grid>
 
-    <!-- 底部：按钮区域 -->
     <Border Grid.Row="1"
-            Background="{DynamicResource CardBackgroundFillColorDefaultBrush}"
-            Padding="24,16">
-      <Grid ColumnDefinitions="*,Auto">
+            Padding="24,16"
+            Background="#171A21">
+      <Grid ColumnDefinitions="*,Auto,Auto,Auto"
+            ColumnSpacing="8">
         <Button x:Name="OpenLogButton"
                 Grid.Column="0"
-                Content="打开日志"
-                Width="100"
-                Height="32"
-                FontSize="13"
-                HorizontalAlignment="Left"/>
-        <StackPanel Grid.Column="1"
-                    Orientation="Horizontal" 
-                    Spacing="8">
-          <Button x:Name="ExitButton"
-                  Content="退出"
-                  Width="80"
-                  Height="32"
-                  FontSize="13"/>
-          <Button x:Name="RetryButton"
-                  Content="重试"
-                  Width="80"
-                  Height="32"
-                  FontSize="13"
-                  Theme="{DynamicResource AccentButtonTheme}"/>
-        </StackPanel>
+                Content="Open Logs"
+                MinWidth="108"
+                Height="34"
+                HorizontalAlignment="Left" />
+
+        <Button x:Name="SecondaryActionButton"
+                Grid.Column="1"
+                Content="Wait"
+                MinWidth="108"
+                Height="34"
+                IsVisible="False" />
+
+        <Button x:Name="ExitButton"
+                Grid.Column="2"
+                Content="Exit"
+                MinWidth="90"
+                Height="34" />
+
+        <Button x:Name="PrimaryActionButton"
+                Grid.Column="3"
+                Content="Retry"
+                MinWidth="108"
+                Height="34" />
       </Grid>
     </Border>
   </Grid>

LanMountainDesktop.Launcher/Views/ErrorWindow.axaml.cs

@@ -1,542 +1,314 @@
+using System.Diagnostics;
 using Avalonia.Controls;
+using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Markup.Xaml;
-using Avalonia.Platform.Storage;
 using LanMountainDesktop.Launcher.Services;
-using System.Diagnostics;
 
 namespace LanMountainDesktop.Launcher.Views;
 
-/// <summary>
-/// 错误窗口 - 显示启动失败信息，支持调试模式（隐藏入口）
-/// </summary>
 public partial class ErrorWindow : Window
 {
-    private readonly TaskCompletionSource<ErrorWindowResult> _completionSource = new();
-    private int _iconClickCount = 0;
     private const int DebugModeClickThreshold = 5;
-    private bool _isDebugMode = false;
-    private string? _customHostPath;
+
+    private readonly TaskCompletionSource<ErrorWindowResult> _completionSource = new(TaskCreationOptions.RunContinuationsAsynchronously);
+    private int _iconClickCount;
+    private bool _isDebugMode;
     private bool _devModeEnabled;
+    private string? _customHostPath;
+    private ErrorWindowResult _primaryAction = ErrorWindowResult.Retry;
+    private ErrorWindowResult? _secondaryAction;
 
     public ErrorWindow()
     {
         AvaloniaXamlLoader.Load(this);
 
-        // 先加载保存的状态
         _devModeEnabled = LoadDevModeStateInternal();
         _customHostPath = LoadCustomHostPathInternal();
 
-        // 延迟到窗口加载完成后再初始化组件，确保视觉树已准备好
-        this.Loaded += OnWindowLoaded;
-        this.Opened += OnWindowOpened;
+        Loaded += OnWindowLoaded;
+        Closed += (_, _) => _completionSource.TrySetResult(ErrorWindowResult.Exit);
+        ConfigureForGenericFailure(allowRetry: true);
     }
 
-    /// <summary>
-    /// 窗口加载完成事件 - 视觉树已准备好
-    /// </summary>
-    private void OnWindowLoaded(object? sender, RoutedEventArgs e)
-    {
-        Console.WriteLine("[ErrorWindow] Window loaded, initializing components...");
-        InitializeComponents();
-    }
-
-    /// <summary>
-    /// 窗口打开事件
-    /// </summary>
-    private void OnWindowOpened(object? sender, EventArgs e)
-    {
-        Console.WriteLine("[ErrorWindow] Window opened and visible");
-    }
-
-    private void InitializeComponents()
-    {
-        Console.WriteLine("[ErrorWindow] Initializing components...");
-        
-        // 错误图标点击事件（进入调试模式 - 隐藏功能）
-        var errorIconBorder = this.FindControl<Border>("ErrorIconBorder");
-        if (errorIconBorder is not null)
-        {
-            errorIconBorder.PointerPressed += OnErrorIconClick;
-            Console.WriteLine("[ErrorWindow] ErrorIconBorder event bound successfully");
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorWindow] Failed to find ErrorIconBorder!");
-        }
-
-        // 按钮事件
-        var retryButton = this.FindControl<Button>("RetryButton");
-        var exitButton = this.FindControl<Button>("ExitButton");
-        var openLogButton = this.FindControl<Button>("OpenLogButton");
-
-        if (retryButton is not null)
-        {
-            retryButton.Click += OnRetryClick;
-            Console.WriteLine("[ErrorWindow] RetryButton event bound");
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorWindow] Failed to find RetryButton!");
-        }
-
-        if (exitButton is not null)
-        {
-            exitButton.Click += OnExitClick;
-            Console.WriteLine("[ErrorWindow] ExitButton event bound");
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorWindow] Failed to find ExitButton!");
-        }
-
-        if (openLogButton is not null)
-        {
-            openLogButton.Click += OnOpenLogClick;
-            Console.WriteLine("[ErrorWindow] OpenLogButton event bound");
-        }
-        else
-        {
-            Console.Error.WriteLine("[ErrorWindow] Failed to find OpenLogButton!");
-        }
-        
-        Console.WriteLine("[ErrorWindow] Components initialization completed");
-    }
-
-    /// <summary>
-    /// 设置错误消息
-    /// </summary>
     public void SetErrorMessage(string message)
     {
-        var errorText = this.FindControl<TextBlock>("ErrorMessageText");
-        if (errorText is not null)
+        if (this.FindControl<TextBlock>("ErrorMessageText") is { } errorText)
         {
             errorText.Text = message;
         }
     }
 
-    /// <summary>
-    /// 设置调试模式
-    /// </summary>
     public void SetDebugMode(bool isDebugMode)
     {
         _isDebugMode = isDebugMode;
-        var titleText = this.FindControl<TextBlock>("TitleText");
-        if (titleText is not null && isDebugMode)
+        if (isDebugMode && this.FindControl<TextBlock>("TitleText") is { } titleText)
         {
-            titleText.Text = "[调试模式] 错误页面";
+            titleText.Text = "[Debug] Launcher error";
         }
     }
 
-    /// <summary>
-    /// 获取用户选择的主程序路径
-    /// </summary>
-    public string? GetCustomHostPath() => _customHostPath;
-
-    /// <summary>
-    /// 是否启用了开发模式
-    /// </summary>
-    public bool IsDevModeEnabled() => _devModeEnabled;
-
-    /// <summary>
-    /// 等待用户选择
-    /// </summary>
-    public Task<ErrorWindowResult> WaitForChoiceAsync()
+    public void ConfigureForHostNotFound()
     {
-        return _completionSource.Task;
+        ApplyActionLayout(
+            title: "Launcher could not find the desktop executable",
+            suggestion: "Pick another executable in debug mode, inspect logs, or retry after fixing the deployment path.",
+            primaryLabel: "Retry",
+            primaryAction: ErrorWindowResult.Retry,
+            secondaryLabel: null,
+            secondaryAction: null);
     }
 
-    /// <summary>
-    /// 错误图标点击事件 - 连续点击 5 次进入调试模式（隐藏功能）
-    /// </summary>
-    private void OnErrorIconClick(object? sender, Avalonia.Input.PointerPressedEventArgs e)
+    public void ConfigureForGenericFailure(bool allowRetry)
+    {
+        ApplyActionLayout(
+            title: "Launcher could not confirm startup",
+            suggestion: allowRetry
+                ? "Inspect logs, then retry once the previous startup attempt has fully finished."
+                : "Inspect logs or exit. Launcher will avoid creating another desktop process while the old one is still running.",
+            primaryLabel: allowRetry ? "Retry" : "Activate",
+            primaryAction: allowRetry ? ErrorWindowResult.Retry : ErrorWindowResult.ActivateExisting,
+            secondaryLabel: allowRetry ? null : "Wait",
+            secondaryAction: allowRetry ? null : ErrorWindowResult.ContinueWaiting);
+    }
+
+    public void ConfigureForRunningHostFailure(int? hostPid)
+    {
+        var pidHint = hostPid is > 0 ? $" Current host PID: {hostPid}." : string.Empty;
+        ApplyActionLayout(
+            title: "Startup is still pending",
+            suggestion: $"The desktop process is still running, so Launcher will not start a second instance.{pidHint}",
+            primaryLabel: "Activate",
+            primaryAction: ErrorWindowResult.ActivateExisting,
+            secondaryLabel: "Wait",
+            secondaryAction: ErrorWindowResult.ContinueWaiting);
+    }
+
+    public string? GetCustomHostPath() => _customHostPath;
+
+    public bool IsDevModeEnabled() => _devModeEnabled;
+
+    public Task<ErrorWindowResult> WaitForChoiceAsync() => _completionSource.Task;
+
+    public static bool CheckDevModeEnabled() => LoadDevModeStateInternal();
+
+    public static string? GetSavedCustomHostPath() => LoadCustomHostPathInternal();
+
+    private void OnWindowLoaded(object? sender, RoutedEventArgs e)
+    {
+        if (this.FindControl<Border>("ErrorIconBorder") is { } errorIconBorder)
+        {
+            errorIconBorder.PointerPressed += OnErrorIconClick;
+        }
+
+        if (this.FindControl<Button>("PrimaryActionButton") is { } primaryActionButton)
+        {
+            primaryActionButton.Click += OnPrimaryActionClick;
+        }
+
+        if (this.FindControl<Button>("SecondaryActionButton") is { } secondaryActionButton)
+        {
+            secondaryActionButton.Click += OnSecondaryActionClick;
+        }
+
+        if (this.FindControl<Button>("ExitButton") is { } exitButton)
+        {
+            exitButton.Click += (_, _) => _completionSource.TrySetResult(ErrorWindowResult.Exit);
+        }
+
+        if (this.FindControl<Button>("OpenLogButton") is { } openLogButton)
+        {
+            openLogButton.Click += OnOpenLogClick;
+        }
+    }
+
+    private void ApplyActionLayout(
+        string title,
+        string suggestion,
+        string primaryLabel,
+        ErrorWindowResult primaryAction,
+        string? secondaryLabel,
+        ErrorWindowResult? secondaryAction)
+    {
+        _primaryAction = primaryAction;
+        _secondaryAction = secondaryAction;
+
+        if (this.FindControl<TextBlock>("TitleText") is { } titleText && !_isDebugMode)
+        {
+            titleText.Text = title;
+        }
+
+        if (this.FindControl<TextBlock>("SuggestionText") is { } suggestionText)
+        {
+            suggestionText.Text = suggestion;
+        }
+
+        if (this.FindControl<Button>("PrimaryActionButton") is { } primaryButton)
+        {
+            primaryButton.Content = primaryLabel;
+        }
+
+        if (this.FindControl<Button>("SecondaryActionButton") is { } secondaryButton)
+        {
+            secondaryButton.IsVisible = !string.IsNullOrWhiteSpace(secondaryLabel);
+            secondaryButton.Content = secondaryLabel ?? string.Empty;
+        }
+    }
+
+    private void OnPrimaryActionClick(object? sender, RoutedEventArgs e)
+    {
+        _completionSource.TrySetResult(_primaryAction);
+    }
+
+    private void OnSecondaryActionClick(object? sender, RoutedEventArgs e)
+    {
+        _completionSource.TrySetResult(_secondaryAction ?? ErrorWindowResult.Exit);
+    }
+
+    private void OnErrorIconClick(object? sender, PointerPressedEventArgs e)
     {
         _iconClickCount++;
-
         if (_iconClickCount >= DebugModeClickThreshold && !_isDebugMode)
         {
             EnterDebugMode();
         }
     }
 
-    /// <summary>
-    /// 进入调试模式 - 显示调试窗口
-    /// </summary>
     private async void EnterDebugMode()
     {
         _isDebugMode = true;
 
-        // 创建并显示调试窗口
         var debugWindow = new ErrorDebugWindow(_devModeEnabled, _customHostPath)
         {
             WindowStartupLocation = WindowStartupLocation.CenterOwner
         };
 
-        // 订阅调试窗口关闭事件
-        debugWindow.Closed += (s, e) =>
+        debugWindow.Closed += (_, _) =>
         {
-            // 更新状态
+            if (!debugWindow.WasAccepted)
+            {
+                _isDebugMode = false;
+                _iconClickCount = 0;
+                return;
+            }
+
             _devModeEnabled = debugWindow.IsDevModeEnabled;
             _customHostPath = debugWindow.SelectedHostPath;
 
-            // 保存开发模式状态和自定义路径
-            SaveDevModeStateInternal(_devModeEnabled);
-            SaveCustomHostPathInternal(_customHostPath);
-
-            // 如果启用了开发模式且没有选择路径，自动扫描
-            if (_devModeEnabled && string.IsNullOrEmpty(_customHostPath))
+            if (_devModeEnabled && string.IsNullOrWhiteSpace(_customHostPath))
             {
                 ScanDevPaths();
-                // 扫描到路径后也保存
-                if (!string.IsNullOrEmpty(_customHostPath))
-                {
-                    SaveCustomHostPathInternal(_customHostPath);
-                }
             }
+
+            LauncherDebugSettingsStore.Save(new LauncherDebugSettings(_devModeEnabled, _customHostPath));
+
+            _isDebugMode = false;
+            _iconClickCount = 0;
         };
 
         await debugWindow.ShowDialog(this);
     }
 
-    /// <summary>
-    /// 扫描开发路径
-    /// </summary>
-    private void ScanDevPaths()
-    {
-        var executable = OperatingSystem.IsWindows() ? "LanMountainDesktop.exe" : "LanMountainDesktop";
-        var possiblePaths = new[]
-        {
-            Path.Combine(AppContext.BaseDirectory, "..", "..", "LanMountainDesktop", "bin", "Debug", "net10.0", executable),
-            Path.Combine(AppContext.BaseDirectory, "..", "..", "LanMountainDesktop", "bin", "Release", "net10.0", executable),
-            Path.Combine(AppContext.BaseDirectory, "..", "LanMountainDesktop", "bin", "Debug", "net10.0", executable),
-            Path.Combine(AppContext.BaseDirectory, "..", "LanMountainDesktop", "bin", "Release", "net10.0", executable),
-            Path.Combine(AppContext.BaseDirectory, "..", "dev-test", "app-1.0.0-dev", executable),
-        };
-
-        foreach (var path in possiblePaths.Select(Path.GetFullPath).Distinct())
-        {
-            if (File.Exists(path))
-            {
-                _customHostPath = path;
-                break;
-            }
-        }
-    }
-
-    /// <summary>
-    /// 获取配置存储的基础目录
-    /// </summary>
-    private static string GetConfigBaseDirectory()
-    {
-        try
-        {
-            // 优先使用 LocalApplicationData（用户状态）
-            var appData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
-            if (!string.IsNullOrEmpty(appData))
-            {
-                var configDir = Path.Combine(appData, "LanMountainDesktop", ".launcher");
-                return configDir;
-            }
-        }
-        catch
-        {
-            // LocalApplicationData 不可用，回退到 Launcher 所在目录
-        }
-
-        // 回退方案：使用 Launcher 所在目录
-        try
-        {
-            var launcherDir = AppContext.BaseDirectory;
-            var configDir = Path.Combine(launcherDir, ".launcher");
-            return configDir;
-        }
-        catch
-        {
-            // 最后的兜底：使用当前目录
-            return Path.Combine(Directory.GetCurrentDirectory(), ".launcher");
-        }
-    }
-
-    /// <summary>
-    /// 确保配置目录存在
-    /// </summary>
-    private static bool EnsureConfigDirectory(string dirPath)
-    {
-        try
-        {
-            if (!Directory.Exists(dirPath))
-            {
-                Directory.CreateDirectory(dirPath);
-                Console.WriteLine($"[ErrorWindow] Created config directory: {dirPath}");
-            }
-            return true;
-        }
-        catch (Exception ex)
-        {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to create config directory: {ex.Message}");
-            return false;
-        }
-    }
-
-    /// <summary>
-    /// 保存开发模式状态（内部方法）
-    /// </summary>
-    private static void SaveDevModeStateInternal(bool enabled)
-    {
-        try
-        {
-            var configDir = GetConfigBaseDirectory();
-            if (!EnsureConfigDirectory(configDir))
-            {
-                Console.Error.WriteLine("[ErrorWindow] Cannot save dev mode: config directory unavailable");
-                return;
-            }
-
-            var devModeFile = Path.Combine(configDir, "devmode.config");
-            File.WriteAllText(devModeFile, enabled ? "1" : "0");
-            Console.WriteLine($"[ErrorWindow] Dev mode state saved: {enabled}");
-        }
-        catch (Exception ex)
-        {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to save dev mode state: {ex.Message}");
-        }
-    }
-
-    /// <summary>
-    /// 加载开发模式状态（内部方法）
-    /// </summary>
-    private static bool LoadDevModeStateInternal()
-    {
-        try
-        {
-            var configDir = GetConfigBaseDirectory();
-            var devModeFile = Path.Combine(configDir, "devmode.config");
-
-            if (File.Exists(devModeFile))
-            {
-                var content = File.ReadAllText(devModeFile).Trim();
-                var enabled = content == "1";
-                Console.WriteLine($"[ErrorWindow] Dev mode state loaded: {enabled}");
-                return enabled;
-            }
-        }
-        catch (Exception ex)
-        {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to load dev mode state: {ex.Message}");
-        }
-        return false;
-    }
-
-    /// <summary>
-    /// 保存自定义主程序路径（内部方法）
-    /// </summary>
-    private static void SaveCustomHostPathInternal(string? path)
-    {
-        try
-        {
-            var configDir = GetConfigBaseDirectory();
-            if (!EnsureConfigDirectory(configDir))
-            {
-                Console.Error.WriteLine("[ErrorWindow] Cannot save custom path: config directory unavailable");
-                return;
-            }
-
-            var hostPathFile = Path.Combine(configDir, "custom-host-path.config");
-            File.WriteAllText(hostPathFile, path ?? string.Empty);
-            Console.WriteLine($"[ErrorWindow] Custom host path saved: {path}");
-        }
-        catch (Exception ex)
-        {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to save custom host path: {ex.Message}");
-        }
-    }
-
-    /// <summary>
-    /// 加载自定义主程序路径（内部方法）
-    /// </summary>
-    private static string? LoadCustomHostPathInternal()
-    {
-        try
-        {
-            var configDir = GetConfigBaseDirectory();
-            var hostPathFile = Path.Combine(configDir, "custom-host-path.config");
-
-            if (File.Exists(hostPathFile))
-            {
-                var content = File.ReadAllText(hostPathFile).Trim();
-                // 验证路径是否仍然有效
-                if (!string.IsNullOrEmpty(content) && File.Exists(content))
-                {
-                    Console.WriteLine($"[ErrorWindow] Custom host path loaded: {content}");
-                    return content;
-                }
-
-                // 路径已失效，清理配置文件
-                if (!string.IsNullOrEmpty(content))
-                {
-                    Console.WriteLine($"[ErrorWindow] Custom host path is no longer valid: {content}");
-                    try
-                    {
-                        File.Delete(hostPathFile);
-                        Console.WriteLine("[ErrorWindow] Cleared invalid custom host path");
-                    }
-                    catch (Exception clearEx)
-                    {
-                        Console.Error.WriteLine($"[ErrorWindow] Failed to clear invalid host path: {clearEx.Message}");
-                    }
-                }
-            }
-        }
-        catch (Exception ex)
-        {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to load custom host path: {ex.Message}");
-        }
-        return null;
-    }
-
-    /// <summary>
-    /// 检查是否启用了开发模式（静态方法，启动时调用）
-    /// </summary>
-    public static bool CheckDevModeEnabled()
-    {
-        return LoadDevModeStateInternal();
-    }
-
-    /// <summary>
-    /// 获取保存的自定义主程序路径（静态方法，启动时调用）
-    /// </summary>
-    public static string? GetSavedCustomHostPath()
-    {
-        return LoadCustomHostPathInternal();
-    }
-
-    private void OnRetryClick(object? sender, RoutedEventArgs e)
-    {
-        _completionSource.TrySetResult(ErrorWindowResult.Retry);
-    }
-
-    private void OnExitClick(object? sender, RoutedEventArgs e)
-    {
-        _completionSource.TrySetResult(ErrorWindowResult.Exit);
-    }
-
-    /// <summary>
-    /// 打开日志文件
-    /// </summary>
     private async void OnOpenLogClick(object? sender, RoutedEventArgs e)
     {
         try
         {
             var logFilePath = Logger.GetLogFilePath();
-
-            if (string.IsNullOrEmpty(logFilePath) || !File.Exists(logFilePath))
+            if (!string.IsNullOrWhiteSpace(logFilePath) && File.Exists(logFilePath))
             {
-                // 如果没有日志文件，打开日志目录
-                var logDir = Path.GetDirectoryName(logFilePath);
-                if (!string.IsNullOrEmpty(logDir) && Directory.Exists(logDir))
-                {
-                    OpenFolder(logDir);
-                }
-                else
-                {
-                    // 尝试打开配置目录
-                    var configDir = GetConfigBaseDirectory();
-                    if (Directory.Exists(configDir))
-                    {
-                        OpenFolder(configDir);
-                    }
-                    else
-                    {
-                        Console.WriteLine("[ErrorWindow] No log file or directory available");
-                    }
-                }
+                OpenPath(logFilePath);
                 return;
             }
 
-            Console.WriteLine($"[ErrorWindow] Opening log file: {logFilePath}");
-            OpenFile(logFilePath);
+            var logDirectory = !string.IsNullOrWhiteSpace(logFilePath)
+                ? Path.GetDirectoryName(logFilePath)
+                : null;
+            if (!string.IsNullOrWhiteSpace(logDirectory) && Directory.Exists(logDirectory))
+            {
+                OpenPath(logDirectory);
+                return;
+            }
+
+            var configDirectory = GetConfigBaseDirectory();
+            if (Directory.Exists(configDirectory))
+            {
+                OpenPath(configDirectory);
+            }
         }
         catch (Exception ex)
         {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to open log: {ex.Message}");
+            Debug.WriteLine($"[ErrorWindow] Failed to open log path: {ex}");
+        }
+
+        await Task.CompletedTask;
+    }
+
+    private void ScanDevPaths()
+    {
+        var executable = OperatingSystem.IsWindows() ? "LanMountainDesktop.exe" : "LanMountainDesktop";
+        var candidatePaths = new[]
+        {
+            Path.Combine(AppContext.BaseDirectory, "..", "..", "LanMountainDesktop", "bin", "Debug", "net10.0", executable),
+            Path.Combine(AppContext.BaseDirectory, "..", "..", "LanMountainDesktop", "bin", "Release", "net10.0", executable),
+            Path.Combine(AppContext.BaseDirectory, "..", "LanMountainDesktop", "bin", "Debug", "net10.0", executable),
+            Path.Combine(AppContext.BaseDirectory, "..", "LanMountainDesktop", "bin", "Release", "net10.0", executable)
+        };
+
+        foreach (var candidate in candidatePaths.Select(Path.GetFullPath).Distinct())
+        {
+            if (File.Exists(candidate))
+            {
+                _customHostPath = candidate;
+                break;
+            }
         }
     }
 
-    /// <summary>
-    /// 打开文件
-    /// </summary>
-    private static void OpenFile(string filePath)
+    private static void OpenPath(string path)
     {
-        try
+        if (OperatingSystem.IsWindows())
         {
-            if (OperatingSystem.IsWindows())
+            Process.Start(new ProcessStartInfo
             {
-                Process.Start(new ProcessStartInfo
-                {
-                    FileName = "explorer.exe",
-                    Arguments = $"\"{filePath}\"",
-                    UseShellExecute = true
-                });
-            }
-            else if (OperatingSystem.IsMacOS())
-            {
-                Process.Start("open", filePath);
-            }
-            else if (OperatingSystem.IsLinux())
-            {
-                Process.Start("xdg-open", filePath);
-            }
+                FileName = "explorer.exe",
+                Arguments = $"\"{path}\"",
+                UseShellExecute = true
+            });
+            return;
         }
-        catch (Exception ex)
+
+        if (OperatingSystem.IsMacOS())
         {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to open file: {ex.Message}");
+            Process.Start("open", path);
+            return;
+        }
+
+        if (OperatingSystem.IsLinux())
+        {
+            Process.Start("xdg-open", path);
         }
     }
 
-    /// <summary>
-    /// 打开文件夹
-    /// </summary>
-    private static void OpenFolder(string folderPath)
+    private static string GetConfigBaseDirectory()
     {
-        try
-        {
-            if (OperatingSystem.IsWindows())
-            {
-                Process.Start(new ProcessStartInfo
-                {
-                    FileName = "explorer.exe",
-                    Arguments = $"\"{folderPath}\"",
-                    UseShellExecute = true
-                });
-            }
-            else if (OperatingSystem.IsMacOS())
-            {
-                Process.Start("open", folderPath);
-            }
-            else if (OperatingSystem.IsLinux())
-            {
-                Process.Start("xdg-open", folderPath);
-            }
-        }
-        catch (Exception ex)
-        {
-            Console.Error.WriteLine($"[ErrorWindow] Failed to open folder: {ex.Message}");
-        }
+        return LauncherDebugSettingsStore.ConfigBaseDirectory;
+    }
+
+    private static bool LoadDevModeStateInternal()
+    {
+        return LauncherDebugSettingsStore.IsDevModeEnabled();
+    }
+
+    private static string? LoadCustomHostPathInternal()
+    {
+        return LauncherDebugSettingsStore.GetSavedCustomHostPath();
     }
 }
 
-/// <summary>
-/// 错误窗口用户选择结果
-/// </summary>
 public enum ErrorWindowResult
 {
-    /// <summary>
-    /// 重试
-    /// </summary>
     Retry,
-
-    /// <summary>
-    /// 退出
-    /// </summary>
-    Exit
+    Exit,
+    ActivateExisting,
+    ContinueWaiting
 }

LanMountainDesktop.Launcher/Views/SplashWindow.axaml

@@ -3,85 +3,92 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:views="clr-namespace:LanMountainDesktop.Launcher.Views"
-        xmlns:ui="using:FluentAvalonia.UI.Controls"
         mc:Ignorable="d"
-        d:DesignWidth="480"
-        d:DesignHeight="320"
         x:Class="LanMountainDesktop.Launcher.Views.SplashWindow"
         x:DataType="views:SplashWindow"
         Title="LanMountain Desktop"
         Width="480"
         Height="320"
         CanResize="False"
+        ShowInTaskbar="False"
         WindowStartupLocation="CenterScreen"
         SystemDecorations="None"
-        Background="{DynamicResource SolidBackgroundFillColorBaseBrush}"
+        Background="#0B0B0B"
         TransparencyLevelHint="None"
         Icon="/Assets/logo.ico">
   <Design.DataContext>
     <views:SplashWindow />
   </Design.DataContext>
 
-  <Grid>
-    <!-- 左上角：应用名称 -->
-    <TextBlock x:Name="AppNameText"
-               Text="LanMountain Desktop"
-               FontSize="24"
-               FontWeight="SemiBold"
-               VerticalAlignment="Top"
-               HorizontalAlignment="Left"
-               Margin="24,24,0,0"
-               Foreground="{DynamicResource TextFillColorPrimaryBrush}" />
-
-    <!-- 底部区域：进度条和状态 -->
-    <Grid VerticalAlignment="Bottom" Margin="24,0,24,24">
-      <Grid.RowDefinitions>
-        <RowDefinition Height="Auto"/>
-        <RowDefinition Height="Auto"/>
-      </Grid.RowDefinitions>
-      
-      <!-- 第一行：左下角版本信息，右下角阶段文字 -->
-      <Grid Grid.Row="0" Margin="0,0,0,8">
-        <Grid.ColumnDefinitions>
-          <ColumnDefinition Width="*"/>
-          <ColumnDefinition Width="Auto"/>
-        </Grid.ColumnDefinitions>
-        
-        <!-- 左下角：版本和开发代号 - 可点击打开开发者界面（隐藏功能） -->
-        <Border x:Name="VersionTextBorder"
-                Grid.Column="0"
-                Background="Transparent"
-                Cursor="Hand"
-                HorizontalAlignment="Left"
-                VerticalAlignment="Bottom">
-          <TextBlock x:Name="VersionText"
-                     FontSize="11"
-                     Foreground="{DynamicResource TextFillColorSecondaryBrush}"
-                     Opacity="0.8"
-                     Text="1.0.0 (Administrate)" />
-        </Border>
-        
-        <!-- 右下角：阶段文字 -->
-        <TextBlock x:Name="StatusText"
-                   Grid.Column="1"
-                   FontSize="11"
-                   Foreground="{DynamicResource TextFillColorSecondaryBrush}"
-                   HorizontalAlignment="Right"
-                   VerticalAlignment="Bottom"
-                   Opacity="0.8"
-                   Text="Initializing..." />
+  <Grid RowDefinitions="*,Auto"
+        Background="#0B0B0B">
+    <Grid Grid.Row="0">
+      <Grid x:Name="CompactHero"
+            Margin="24">
+        <TextBlock x:Name="AppNameText"
+                   Text="LanMountain Desktop"
+                   FontSize="24"
+                   FontWeight="SemiBold"
+                   VerticalAlignment="Top"
+                   HorizontalAlignment="Left"
+                   Foreground="#F6F7FB" />
+      </Grid>
+
+      <Grid x:Name="FullscreenHero"
+            IsVisible="False">
+        <StackPanel HorizontalAlignment="Center"
+                    VerticalAlignment="Center"
+                    Spacing="24">
+          <Border Width="240"
+                  Height="240"
+                  Background="Transparent">
+            <Image Source="/Assets/logo_nightly.png"
+                   Stretch="Uniform" />
+          </Border>
+
+          <TextBlock Text="LanMountain Desktop"
+                     HorizontalAlignment="Center"
+                     FontSize="26"
+                     FontWeight="SemiBold"
+                     Foreground="#F6F7FB" />
+        </StackPanel>
       </Grid>
-      
-      <!-- 底部：进度条 -->
-      <ProgressBar x:Name="ProgressIndicator"
-                   Grid.Row="1"
-                   Minimum="0"
-                   Maximum="100"
-                   Value="0"
-                   Height="4"
-                   IsIndeterminate="False"
-                   Foreground="{DynamicResource AccentFillColorDefaultBrush}"
-                   Background="{DynamicResource ControlStrokeColorDefaultBrush}" />
     </Grid>
+
+    <Border Grid.Row="1"
+            Padding="24,18,24,24"
+            Background="Transparent">
+      <Grid RowDefinitions="Auto,Auto"
+            RowSpacing="10">
+        <Grid ColumnDefinitions="*,Auto">
+          <Border x:Name="VersionTextBorder"
+                  Background="Transparent"
+                  Cursor="Hand"
+                  HorizontalAlignment="Left">
+            <TextBlock x:Name="VersionText"
+                       FontSize="11"
+                       Foreground="#B9C0CC"
+                       Text="0.0.0-dev (Administrate)" />
+          </Border>
+
+          <TextBlock x:Name="StatusText"
+                     Grid.Column="1"
+                     FontSize="11"
+                     Foreground="#B9C0CC"
+                     HorizontalAlignment="Right"
+                     Text="Initializing..." />
+        </Grid>
+
+        <ProgressBar x:Name="ProgressIndicator"
+                     Grid.Row="1"
+                     Minimum="0"
+                     Maximum="100"
+                     Value="0"
+                     Height="4"
+                     IsIndeterminate="False"
+                     Foreground="#F6F7FB"
+                     Background="#2C313D" />
+      </Grid>
+    </Border>
   </Grid>
 </Window>

LanMountainDesktop.Launcher/Views/SplashWindow.axaml.cs

@@ -1,88 +1,273 @@
+using System.Diagnostics;
+using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Markup.Xaml;
+using Avalonia.Media;
 using Avalonia.Threading;
 using LanMountainDesktop.Launcher.Services;
+using LanMountainDesktop.Shared.Contracts.Launcher;
 
 namespace LanMountainDesktop.Launcher.Views;
 
-/// <summary>
-/// 启动画面窗口 - 简洁设计
-/// </summary>
 public partial class SplashWindow : Window, ISplashStageReporter
 {
-    private int _versionTextClickCount = 0;
     private const int DebugModeClickThreshold = 5;
-    private bool _isDebugModeOpened = false;
+    private static readonly TimeSpan FadeAnimationDuration = TimeSpan.FromMilliseconds(160);
+    private static readonly TimeSpan SlideAnimationDuration = TimeSpan.FromMilliseconds(260);
+
+    private readonly StartupVisualMode _mode;
+    private int _versionTextClickCount;
+    private bool _isDebugModeOpened;
+    private bool _isOpened;
+    private bool _layoutConfigured;
+    private bool _dismissed;
+    private PixelPoint _targetPosition;
+    private PixelPoint _slideHiddenPosition;
 
     public SplashWindow()
+        : this(StartupVisualMode.Fade)
     {
-        AvaloniaXamlLoader.Load(this);
-        
-        // 延迟到窗口加载完成后再绑定事件
-        this.Loaded += OnWindowLoaded;
     }
 
-    /// <summary>
-    /// 窗口加载完成事件
-    /// </summary>
+    public SplashWindow(StartupVisualMode mode)
+    {
+        _mode = mode;
+        AvaloniaXamlLoader.Load(this);
+        Loaded += OnWindowLoaded;
+        Opened += OnWindowOpened;
+    }
+
     private void OnWindowLoaded(object? sender, RoutedEventArgs e)
     {
-        Console.WriteLine("[SplashWindow] Window loaded, binding events...");
-        
-        // 绑定版本文本点击事件（隐藏功能：点击5次打开开发者界面）
-        var versionTextBorder = this.FindControl<Border>("VersionTextBorder");
-        if (versionTextBorder is not null)
+        if (this.FindControl<Border>("VersionTextBorder") is { } versionBorder)
         {
-            versionTextBorder.PointerPressed += OnVersionTextClick;
-            Console.WriteLine("[SplashWindow] VersionTextBorder click event bound");
-        }
-        else
-        {
-            Console.Error.WriteLine("[SplashWindow] Failed to find VersionTextBorder!");
+            versionBorder.PointerPressed += OnVersionTextClick;
         }
     }
 
-    /// <summary>
-    /// 版本文本点击事件 - 连续点击5次打开开发者界面（隐藏功能）
-    /// </summary>
+    private async void OnWindowOpened(object? sender, EventArgs e)
+    {
+        if (_isOpened)
+        {
+            return;
+        }
+
+        _isOpened = true;
+        ConfigureForVisualMode();
+
+        if (_mode == StartupVisualMode.Fade)
+        {
+            Opacity = 0d;
+            await AnimateOpacityAsync(0d, 1d, FadeAnimationDuration).ConfigureAwait(false);
+            return;
+        }
+
+        Opacity = 1d;
+        if (_mode == StartupVisualMode.SlideSplash)
+        {
+            await AnimateWindowPositionAsync(_slideHiddenPosition, _targetPosition, SlideAnimationDuration, EaseOutCubic).ConfigureAwait(false);
+        }
+    }
+
+    public async Task DismissAsync()
+    {
+        if (_dismissed)
+        {
+            return;
+        }
+
+        _dismissed = true;
+        ConfigureForVisualMode();
+
+        if (_mode == StartupVisualMode.SlideSplash)
+        {
+            var from = Position;
+            await AnimateWindowPositionAsync(from, _slideHiddenPosition, SlideAnimationDuration, EaseInCubic).ConfigureAwait(false);
+        }
+        else if (_mode == StartupVisualMode.Fade)
+        {
+            await AnimateOpacityAsync(Opacity, 0d, FadeAnimationDuration).ConfigureAwait(false);
+        }
+
+        await Dispatcher.UIThread.InvokeAsync(() =>
+        {
+            if (IsVisible)
+            {
+                Close();
+            }
+        });
+    }
+
+    public void Report(string stage, string message)
+    {
+        Dispatcher.UIThread.Post(() =>
+        {
+            if (this.FindControl<TextBlock>("StatusText") is { } statusText)
+            {
+                statusText.Text = message;
+            }
+
+            if (this.FindControl<ProgressBar>("ProgressIndicator") is { } progressIndicator)
+            {
+                var progress = ResolveProgress(stage);
+                if (progress > 0)
+                {
+                    progressIndicator.IsIndeterminate = false;
+                    progressIndicator.Value = progress;
+                }
+                else
+                {
+                    progressIndicator.IsIndeterminate = true;
+                }
+            }
+        });
+    }
+
+    public void ReportStage(string stage, int progress)
+    {
+        Dispatcher.UIThread.Post(() =>
+        {
+            if (this.FindControl<TextBlock>("StatusText") is { } statusText)
+            {
+                statusText.Text = stage;
+            }
+
+            if (this.FindControl<ProgressBar>("ProgressIndicator") is { } progressIndicator)
+            {
+                progressIndicator.IsIndeterminate = false;
+                progressIndicator.Value = Math.Clamp(progress, 0, 100);
+            }
+        });
+    }
+
+    public void UpdateProgress(int percent, string? message = null)
+    {
+        Dispatcher.UIThread.Post(() =>
+        {
+            if (!string.IsNullOrWhiteSpace(message) &&
+                this.FindControl<TextBlock>("StatusText") is { } statusText)
+            {
+                statusText.Text = message;
+            }
+
+            if (this.FindControl<ProgressBar>("ProgressIndicator") is { } progressIndicator)
+            {
+                progressIndicator.IsIndeterminate = false;
+                progressIndicator.Value = Math.Clamp(percent, 0, 100);
+            }
+        });
+    }
+
+    public void UpdateStatus(string message)
+    {
+        Dispatcher.UIThread.Post(() =>
+        {
+            if (this.FindControl<TextBlock>("StatusText") is { } statusText)
+            {
+                statusText.Text = message;
+            }
+        });
+    }
+
+    public void SetVersionInfo(string version, string codename)
+    {
+        Dispatcher.UIThread.Post(() =>
+        {
+            if (this.FindControl<TextBlock>("VersionText") is { } versionText)
+            {
+                versionText.Text = $"{version} ({codename})";
+            }
+        });
+    }
+
+    public void SetDebugMode(bool isDebugMode)
+    {
+        if (!isDebugMode)
+        {
+            return;
+        }
+
+        UpdateStatus("[Debug Mode] Splash Preview");
+    }
+
+    private void ConfigureForVisualMode()
+    {
+        if (_layoutConfigured)
+        {
+            return;
+        }
+
+        _layoutConfigured = true;
+        var compactHero = this.FindControl<Grid>("CompactHero");
+        var fullscreenHero = this.FindControl<Grid>("FullscreenHero");
+
+        if (_mode == StartupVisualMode.Fade)
+        {
+            compactHero?.SetCurrentValue(IsVisibleProperty, true);
+            fullscreenHero?.SetCurrentValue(IsVisibleProperty, false);
+            Background = new SolidColorBrush(Color.Parse("#0B0B0B"));
+            Width = 480;
+            Height = 320;
+            WindowStartupLocation = WindowStartupLocation.CenterScreen;
+            return;
+        }
+
+        compactHero?.SetCurrentValue(IsVisibleProperty, false);
+        fullscreenHero?.SetCurrentValue(IsVisibleProperty, true);
+        Background = Brushes.Black;
+        WindowStartupLocation = WindowStartupLocation.Manual;
+
+        var screen = Screens?.Primary ?? Screens?.All.FirstOrDefault();
+        var workingArea = screen?.WorkingArea ?? new PixelRect(0, 0, 1920, 1080);
+        var scale = Math.Max(screen?.Scaling ?? 1d, 0.01d);
+
+        Width = workingArea.Width / scale;
+        Height = workingArea.Height / scale;
+        _targetPosition = new PixelPoint(workingArea.X, workingArea.Y);
+        _slideHiddenPosition = new PixelPoint(workingArea.X + workingArea.Width, workingArea.Y);
+        Position = _mode == StartupVisualMode.SlideSplash
+            ? _slideHiddenPosition
+            : _targetPosition;
+    }
+
     private void OnVersionTextClick(object? sender, PointerPressedEventArgs e)
     {
-        if (_isDebugModeOpened) return;
-        
-        _versionTextClickCount++;
-        Console.WriteLine($"[SplashWindow] Version text clicked {_versionTextClickCount}/{DebugModeClickThreshold}");
+        if (_isDebugModeOpened)
+        {
+            return;
+        }
 
+        _versionTextClickCount++;
         if (_versionTextClickCount >= DebugModeClickThreshold)
         {
             OpenDebugWindow();
         }
     }
 
-    /// <summary>
-    /// 打开开发者调试窗口
-    /// </summary>
     private async void OpenDebugWindow()
     {
         _isDebugModeOpened = true;
-        Console.WriteLine("[SplashWindow] Opening debug window...");
 
         try
         {
-            // 加载保存的状态
-            var devModeEnabled = ErrorWindow.CheckDevModeEnabled();
-            var customHostPath = ErrorWindow.GetSavedCustomHostPath();
-
-            var debugWindow = new ErrorDebugWindow(devModeEnabled, customHostPath)
+            var debugWindow = new ErrorDebugWindow(
+                ErrorWindow.CheckDevModeEnabled(),
+                ErrorWindow.GetSavedCustomHostPath())
             {
-                WindowStartupLocation = WindowStartupLocation.CenterScreen
+                WindowStartupLocation = WindowStartupLocation.CenterOwner
             };
 
-            // 订阅窗口关闭事件以保存状态
-            debugWindow.Closed += (s, e) =>
+            debugWindow.Closed += (_, _) =>
             {
-                Console.WriteLine("[SplashWindow] Debug window closed");
+                if (debugWindow.WasAccepted)
+                {
+                    LauncherDebugSettingsStore.Save(new LauncherDebugSettings(
+                        debugWindow.IsDevModeEnabled,
+                        debugWindow.SelectedHostPath));
+                }
+
                 _isDebugModeOpened = false;
                 _versionTextClickCount = 0;
             };
@@ -91,160 +276,75 @@ public partial class SplashWindow : Window, ISplashStageReporter
         }
         catch (Exception ex)
         {
-            Console.Error.WriteLine($"[SplashWindow] Error opening debug window: {ex.Message}");
+            Debug.WriteLine($"[SplashWindow] Failed to open debug window: {ex}");
             _isDebugModeOpened = false;
             _versionTextClickCount = 0;
         }
     }
 
-    /// <summary>
-    /// 更新进度和状态
-    /// </summary>
-    public void Report(string stage, string message)
+    private async Task AnimateOpacityAsync(double from, double to, TimeSpan duration)
     {
-        Dispatcher.UIThread.Post(() =>
+        await AnimateAsync(progress =>
         {
-            var statusText = this.FindControl<TextBlock>("StatusText");
-            var progressIndicator = this.FindControl<ProgressBar>("ProgressIndicator");
-            
-            if (statusText is null || progressIndicator is null)
-            {
-                Console.Error.WriteLine($"[SplashWindow] Controls not found: StatusText={statusText != null}, ProgressIndicator={progressIndicator != null}");
-                return;
-            }
-
-            // 更新状态文本
-            statusText.Text = message;
-
-            // 根据阶段更新进度
-            var progress = ResolveProgress(stage);
-            if (progress > 0)
-            {
-                progressIndicator.IsIndeterminate = false;
-                progressIndicator.Value = progress;
-            }
-            else
-            {
-                progressIndicator.IsIndeterminate = true;
-            }
-        });
+            Opacity = from + ((to - from) * progress);
+        }, duration, EaseOutCubic).ConfigureAwait(false);
     }
 
-    /// <summary>
-    /// 更新进度（0-100）
-    /// </summary>
-    public void UpdateProgress(int percent, string? message = null)
+    private async Task AnimateWindowPositionAsync(
+        PixelPoint from,
+        PixelPoint to,
+        TimeSpan duration,
+        Func<double, double> easing)
     {
-        Dispatcher.UIThread.Post(() =>
+        await AnimateAsync(progress =>
         {
-            var statusText = this.FindControl<TextBlock>("StatusText");
-            var progressIndicator = this.FindControl<ProgressBar>("ProgressIndicator");
-            
-            if (statusText is null || progressIndicator is null)
-            {
-                Console.Error.WriteLine($"[SplashWindow] Controls not found in UpdateProgress");
-                return;
-            }
-
-            if (!string.IsNullOrEmpty(message))
-            {
-                statusText.Text = message;
-            }
-
-            progressIndicator.IsIndeterminate = false;
-            progressIndicator.Value = Math.Clamp(percent, 0, 100);
-        });
+            var currentX = (int)Math.Round(from.X + ((to.X - from.X) * progress));
+            var currentY = (int)Math.Round(from.Y + ((to.Y - from.Y) * progress));
+            Position = new PixelPoint(currentX, currentY);
+        }, duration, easing).ConfigureAwait(false);
     }
 
-    /// <summary>
-    /// 更新状态文本
-    /// </summary>
-    public void UpdateStatus(string message)
+    private async Task AnimateAsync(Action<double> update, TimeSpan duration, Func<double, double> easing)
     {
-        Dispatcher.UIThread.Post(() =>
+        if (duration <= TimeSpan.Zero)
         {
-            var statusText = this.FindControl<TextBlock>("StatusText");
-            if (statusText is null)
-            {
-                Console.Error.WriteLine($"[SplashWindow] StatusText not found in UpdateStatus");
-                return;
-            }
-            statusText.Text = message;
-        });
+            await Dispatcher.UIThread.InvokeAsync(() => update(1d));
+            return;
+        }
+
+        var stopwatch = Stopwatch.StartNew();
+        while (stopwatch.Elapsed < duration)
+        {
+            var raw = stopwatch.Elapsed.TotalMilliseconds / duration.TotalMilliseconds;
+            var progress = easing(Math.Clamp(raw, 0d, 1d));
+            await Dispatcher.UIThread.InvokeAsync(() => update(progress));
+            await Task.Delay(16).ConfigureAwait(false);
+        }
+
+        await Dispatcher.UIThread.InvokeAsync(() => update(1d));
     }
 
-    /// <summary>
-    /// 报告阶段和进度（0-100）
-    /// </summary>
-    public void ReportStage(string stage, int progress)
-    {
-        Dispatcher.UIThread.Post(() =>
-        {
-            var statusText = this.FindControl<TextBlock>("StatusText");
-            var progressIndicator = this.FindControl<ProgressBar>("ProgressIndicator");
-            
-            if (statusText is null || progressIndicator is null)
-            {
-                Console.Error.WriteLine($"[SplashWindow] Controls not found in ReportStage");
-                return;
-            }
-
-            statusText.Text = stage;
-            progressIndicator.IsIndeterminate = false;
-            progressIndicator.Value = Math.Clamp(progress, 0, 100);
-        });
-    }
-
-    /// <summary>
-    /// 设置版本和开发代号
-    /// </summary>
-    public void SetVersionInfo(string version, string codename)
-    {
-        Dispatcher.UIThread.Post(() =>
-        {
-            var versionText = this.FindControl<TextBlock>("VersionText");
-            if (versionText is null)
-            {
-                Console.Error.WriteLine($"[SplashWindow] VersionText not found in SetVersionInfo");
-                return;
-            }
-            versionText.Text = $"{version} ({codename})";
-        });
-    }
-
-    /// <summary>
-    /// 设置调试模式
-    /// </summary>
-    public void SetDebugMode(bool isDebugMode)
-    {
-        Dispatcher.UIThread.Post(() =>
-        {
-            var statusText = this.FindControl<TextBlock>("StatusText");
-            if (statusText is null)
-            {
-                Console.Error.WriteLine($"[SplashWindow] StatusText not found in SetDebugMode");
-                return;
-            }
-            if (isDebugMode)
-            {
-                statusText.Text = "[Debug Mode] Splash Preview";
-            }
-        });
-    }
-
-    /// <summary>
-    /// 根据阶段名称解析进度值
-    /// </summary>
     private static int ResolveProgress(string stage)
     {
         return stage.ToLowerInvariant() switch
         {
             "initializing" => 10,
+            "settings" => 25,
             "update" => 30,
             "plugins" => 50,
-            "launch" => 70,
+            "ui" => 65,
+            "shell" => 80,
+            "activation" => 90,
             "ready" => 100,
             _ => 0
         };
     }
+
+    private static double EaseOutCubic(double value)
+    {
+        var inverse = 1d - value;
+        return 1d - (inverse * inverse * inverse);
+    }
+
+    private static double EaseInCubic(double value) => value * value * value;
 }

LanMountainDesktop.Shared.Contracts/Launcher/AppVersionProvider.cs

@@ -108,7 +108,9 @@ public static class AppVersionProvider
             return fallback;
         }
 
-        var normalized = rawValue.Split('+', 2, StringSplitOptions.TrimEntries)[0].Trim();
+        var normalized = TrimSurroundingQuotes(rawValue)
+            .Split('+', 2, StringSplitOptions.TrimEntries)[0]
+            .Trim();
         return string.IsNullOrWhiteSpace(normalized)
             ? fallback
             : normalized;
@@ -116,9 +118,10 @@ public static class AppVersionProvider
 
     public static string NormalizeCodename(string? rawValue, string fallback = DefaultCodename)
     {
-        return string.IsNullOrWhiteSpace(rawValue)
+        var normalized = TrimSurroundingQuotes(rawValue);
+        return string.IsNullOrWhiteSpace(normalized)
             ? fallback
-            : rawValue.Trim();
+            : normalized;
     }
 
     private static AppVersionInfo OverrideMissingParts(
@@ -158,17 +161,24 @@ public static class AppVersionProvider
 
         try
         {
-            var json = File.ReadAllText(versionFilePath);
-            var parsedInfo = JsonSerializer.Deserialize<AppVersionInfo>(json);
-            if (parsedInfo is null || string.IsNullOrWhiteSpace(parsedInfo.Version))
+            using var document = JsonDocument.Parse(File.ReadAllText(versionFilePath));
+            var root = document.RootElement;
+            if (root.ValueKind != JsonValueKind.Object)
             {
                 return false;
             }
 
+            var version = ReadStringProperty(root, nameof(AppVersionInfo.Version));
+            if (string.IsNullOrWhiteSpace(version))
+            {
+                return false;
+            }
+
+            var codename = ReadStringProperty(root, nameof(AppVersionInfo.Codename));
             info = new AppVersionInfo
             {
-                Version = NormalizeVersionText(parsedInfo.Version),
-                Codename = NormalizeCodename(parsedInfo.Codename)
+                Version = NormalizeVersionText(version),
+                Codename = NormalizeCodename(codename)
             };
             return true;
         }
@@ -359,4 +369,43 @@ public static class AppVersionProvider
             return null;
         }
     }
+
+    private static string? ReadStringProperty(JsonElement root, string propertyName)
+    {
+        foreach (var property in root.EnumerateObject())
+        {
+            if (string.Equals(property.Name, propertyName, StringComparison.OrdinalIgnoreCase) &&
+                property.Value.ValueKind == JsonValueKind.String)
+            {
+                return property.Value.GetString();
+            }
+        }
+
+        return null;
+    }
+
+    private static string TrimSurroundingQuotes(string? rawValue)
+    {
+        if (string.IsNullOrWhiteSpace(rawValue))
+        {
+            return string.Empty;
+        }
+
+        var normalized = rawValue.Trim();
+        while (normalized.Length >= 2)
+        {
+            var first = normalized[0];
+            var last = normalized[^1];
+            if ((first == '\'' && last == '\'') ||
+                (first == '"' && last == '"'))
+            {
+                normalized = normalized[1..^1].Trim();
+                continue;
+            }
+
+            break;
+        }
+
+        return normalized;
+    }
 }

LanMountainDesktop.Shared.Contracts/Launcher/LoadingState.cs

@@ -1,231 +1,85 @@
 namespace LanMountainDesktop.Shared.Contracts.Launcher;
 
-/// <summary>
-/// 加载项类型
-/// </summary>
 public enum LoadingItemType
 {
-    /// <summary>
-    /// 系统初始化
-    /// </summary>
     System,
-    
-    /// <summary>
-    /// 设置加载
-    /// </summary>
     Settings,
-    
-    /// <summary>
-    /// 插件
-    /// </summary>
     Plugin,
-    
-    /// <summary>
-    /// 组件
-    /// </summary>
     Component,
-    
-    /// <summary>
-    /// 资源
-    /// </summary>
     Resource,
-    
-    /// <summary>
-    /// 数据
-    /// </summary>
     Data,
-    
-    /// <summary>
-    /// 网络请求
-    /// </summary>
     Network,
-    
-    /// <summary>
-    /// 其他
-    /// </summary>
     Other
 }
 
-/// <summary>
-/// 加载状态
-/// </summary>
 public enum LoadingState
 {
-    /// <summary>
-    /// 等待中
-    /// </summary>
     Pending,
-    
-    /// <summary>
-    /// 进行中
-    /// </summary>
     InProgress,
-    
-    /// <summary>
-    /// 已完成
-    /// </summary>
     Completed,
-    
-    /// <summary>
-    /// 失败
-    /// </summary>
+    Delayed,
     Failed,
-    
-    /// <summary>
-    /// 已取消
-    /// </summary>
     Cancelled,
-    
-    /// <summary>
-    /// 超时
-    /// </summary>
     Timeout
 }
 
-/// <summary>
-/// 加载项信息
-/// </summary>
 public record LoadingItem
 {
-    /// <summary>
-    /// 加载项唯一标识
-    /// </summary>
     public required string Id { get; init; }
-    
-    /// <summary>
-    /// 加载项类型
-    /// </summary>
+
     public LoadingItemType Type { get; init; }
-    
-    /// <summary>
-    /// 加载项名称
-    /// </summary>
+
     public required string Name { get; init; }
-    
-    /// <summary>
-    /// 加载项描述
-    /// </summary>
+
     public string? Description { get; init; }
-    
-    /// <summary>
-    /// 当前状态
-    /// </summary>
+
     public LoadingState State { get; init; }
-    
-    /// <summary>
-    /// 进度百分比 (0-100)
-    /// </summary>
+
     public int ProgressPercent { get; init; }
-    
-    /// <summary>
-    /// 状态消息
-    /// </summary>
+
     public string? Message { get; init; }
-    
-    /// <summary>
-    /// 错误信息（当 State 为 Failed 时）
-    /// </summary>
+
     public string? ErrorMessage { get; init; }
-    
-    /// <summary>
-    /// 开始时间
-    /// </summary>
+
     public DateTimeOffset? StartTime { get; init; }
-    
-    /// <summary>
-    /// 结束时间
-    /// </summary>
+
     public DateTimeOffset? EndTime { get; init; }
-    
-    /// <summary>
-    /// 预计剩余时间（秒）
-    /// </summary>
+
     public int? EstimatedRemainingSeconds { get; init; }
-    
-    /// <summary>
-    /// 子加载项
-    /// </summary>
+
     public List<LoadingItem>? Children { get; init; }
-    
-    /// <summary>
-    /// 额外数据
-    /// </summary>
+
     public Dictionary<string, string>? Metadata { get; init; }
-    
-    /// <summary>
-    /// 时间戳
-    /// </summary>
+
     public DateTimeOffset Timestamp { get; init; } = DateTimeOffset.UtcNow;
 }
 
-/// <summary>
-/// 加载状态更新消息
-/// </summary>
 public record LoadingStateMessage
 {
-    /// <summary>
-    /// 当前启动阶段
-    /// </summary>
     public StartupStage Stage { get; init; }
-    
-    /// <summary>
-    /// 整体进度百分比 (0-100)
-    /// </summary>
+
     public int OverallProgressPercent { get; init; }
-    
-    /// <summary>
-    /// 当前活动的加载项
-    /// </summary>
+
     public List<LoadingItem> ActiveItems { get; init; } = new();
-    
-    /// <summary>
-    /// 已完成的加载项数量
-    /// </summary>
+
     public int CompletedCount { get; init; }
-    
-    /// <summary>
-    /// 总加载项数量
-    /// </summary>
+
     public int TotalCount { get; init; }
-    
-    /// <summary>
-    /// 状态消息
-    /// </summary>
+
     public string? Message { get; init; }
-    
-    /// <summary>
-    /// 是否有错误
-    /// </summary>
+
     public bool HasErrors { get; init; }
-    
-    /// <summary>
-    /// 错误消息列表
-    /// </summary>
+
     public List<string>? ErrorMessages { get; init; }
-    
-    /// <summary>
-    /// 时间戳
-    /// </summary>
+
     public DateTimeOffset Timestamp { get; init; } = DateTimeOffset.UtcNow;
 }
 
-/// <summary>
-/// 详细的加载进度消息（用于实时更新）
-/// </summary>
 public record DetailedProgressMessage : StartupProgressMessage
 {
-    /// <summary>
-    /// 当前加载项
-    /// </summary>
     public LoadingItem? CurrentItem { get; init; }
-    
-    /// <summary>
-    /// 所有加载项
-    /// </summary>
+
     public List<LoadingItem>? AllItems { get; init; }
-    
-    /// <summary>
-    /// 是否为主要更新
-    /// </summary>
+
     public bool IsMajorUpdate { get; init; }
 }

LanMountainDesktop.Shared.Contracts/Launcher/StartupVisualPreferences.cs

@@ -0,0 +1,91 @@
+using System.Text.Json;
+
+namespace LanMountainDesktop.Shared.Contracts.Launcher;
+
+public enum StartupVisualMode
+{
+    Fade,
+    StaticSplash,
+    SlideSplash
+}
+
+public readonly record struct StartupVisualPreferences(
+    bool EnableFadeTransition,
+    bool EnableSlideTransition)
+{
+    public static StartupVisualPreferences Default => new(true, false);
+
+    public StartupVisualPreferences Normalize()
+    {
+        if (EnableSlideTransition)
+        {
+            return new StartupVisualPreferences(false, true);
+        }
+
+        return new StartupVisualPreferences(EnableFadeTransition, false);
+    }
+
+    public StartupVisualMode Mode => Normalize() switch
+    {
+        { EnableSlideTransition: true } => StartupVisualMode.SlideSplash,
+        { EnableFadeTransition: false } => StartupVisualMode.StaticSplash,
+        _ => StartupVisualMode.Fade
+    };
+}
+
+public static class StartupVisualPreferencesResolver
+{
+    public static StartupVisualPreferences Resolve(string? settingsPath = null)
+    {
+        var resolvedPath = string.IsNullOrWhiteSpace(settingsPath)
+            ? GetDefaultSettingsPath()
+            : settingsPath!;
+
+        if (!File.Exists(resolvedPath))
+        {
+            return StartupVisualPreferences.Default;
+        }
+
+        try
+        {
+            using var stream = File.OpenRead(resolvedPath);
+            using var document = JsonDocument.Parse(stream);
+            var root = document.RootElement;
+
+            var enableFade = TryGetBoolean(root, "enableFadeTransition") ?? true;
+            var enableSlide = TryGetBoolean(root, "enableSlideTransition") ?? false;
+            return FromFlags(enableFade, enableSlide);
+        }
+        catch
+        {
+            return StartupVisualPreferences.Default;
+        }
+    }
+
+    public static StartupVisualPreferences FromFlags(bool enableFadeTransition, bool enableSlideTransition)
+    {
+        return new StartupVisualPreferences(enableFadeTransition, enableSlideTransition).Normalize();
+    }
+
+    public static string GetDefaultSettingsPath()
+    {
+        var appData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+        return Path.Combine(appData, "LanMountainDesktop", "settings.json");
+    }
+
+    private static bool? TryGetBoolean(JsonElement root, string propertyName)
+    {
+        if (!root.TryGetProperty(propertyName, out var property))
+        {
+            return null;
+        }
+
+        return property.ValueKind switch
+        {
+            JsonValueKind.True => true,
+            JsonValueKind.False => false,
+            JsonValueKind.String when bool.TryParse(property.GetString(), out var value) => value,
+            _ => null
+        };
+    }
+}

LanMountainDesktop.Shared.IPC/Abstractions/Services/IPublicShellControlService.cs

@@ -5,8 +5,16 @@ namespace LanMountainDesktop.Shared.IPC.Abstractions.Services;
 [IpcPublic(IgnoresIpcException = true)]
 public interface IPublicShellControlService
 {
+    Task<PublicShellStatus> GetShellStatusAsync();
+
     Task<bool> ActivateMainWindowAsync();
 
+    Task<PublicShellActivationResult> ActivateMainWindowWithStatusAsync();
+
+    Task<PublicTrayStatus> EnsureTrayReadyAsync();
+
+    Task<PublicTaskbarStatus> EnsureTaskbarEntryAsync();
+
     Task<bool> OpenSettingsAsync(string? pageTag = null);
 
     Task<bool> RestartAsync();

LanMountainDesktop.Shared.IPC/Abstractions/Services/PublicShellStatus.cs

@@ -0,0 +1,36 @@
+namespace LanMountainDesktop.Shared.IPC.Abstractions.Services;
+
+public sealed record PublicShellStatus(
+    int ProcessId,
+    DateTimeOffset StartedAtUtc,
+    string LaunchSource,
+    string ShellState,
+    bool MainWindowCreated,
+    bool MainWindowVisible,
+    bool MainWindowOpened,
+    bool DesktopVisible,
+    bool PublicIpcReady,
+    PublicTrayStatus Tray,
+    PublicTaskbarStatus Taskbar);
+
+public sealed record PublicTrayStatus(
+    string State,
+    bool IsReady,
+    bool HasIcon,
+    bool HasMenu,
+    bool IsVisible,
+    int ConsecutiveRecoveryFailures);
+
+public sealed record PublicTaskbarStatus(
+    bool RequestedBySettings,
+    bool MainWindowExists,
+    bool MainWindowShowInTaskbar,
+    bool MainWindowVisible,
+    bool MainWindowMinimized,
+    bool IsUsable);
+
+public sealed record PublicShellActivationResult(
+    bool Accepted,
+    string Code,
+    string Message,
+    PublicShellStatus Status);

LanMountainDesktop.Tests/AppVersionProviderTests.cs

@@ -0,0 +1,83 @@
+using LanMountainDesktop.Shared.Contracts.Launcher;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+public sealed class AppVersionProviderTests
+{
+    [Fact]
+    public void ResolveFromPackageRoot_WhenVersionJsonExists_UsesVersionFile()
+    {
+        using var temp = TemporaryPackage.Create();
+        temp.CreateDeployment("app-0.8.5.7", """
+        {"Version":"0.8.5.7","Codename":"Administrate"}
+        """);
+
+        var info = AppVersionProvider.ResolveFromPackageRoot(temp.Root, "LanMountainDesktop.exe");
+
+        Assert.Equal("0.8.5.7", info.Version);
+        Assert.Equal("Administrate", info.Codename);
+    }
+
+    [Fact]
+    public void ResolveFromPackageRoot_WhenVersionJsonIsMissing_FallsBackToDeploymentDirectory()
+    {
+        using var temp = TemporaryPackage.Create();
+        temp.CreateDeployment("app-0.8.5.7");
+
+        var info = AppVersionProvider.ResolveFromPackageRoot(temp.Root, "LanMountainDesktop.exe");
+
+        Assert.Equal("0.8.5.7", info.Version);
+    }
+
+    [Fact]
+    public void ResolveFromPackageRoot_WhenVersionJsonContainsQuotedValues_NormalizesValues()
+    {
+        using var temp = TemporaryPackage.Create();
+        temp.CreateDeployment("app-1.2.3", """
+        {"Version":"'1.2.3'","Codename":"'Administrate'"}
+        """);
+
+        var info = AppVersionProvider.ResolveFromPackageRoot(temp.Root, "LanMountainDesktop.exe");
+
+        Assert.Equal("1.2.3", info.Version);
+        Assert.Equal("Administrate", info.Codename);
+    }
+
+    private sealed class TemporaryPackage : IDisposable
+    {
+        private TemporaryPackage(string root)
+        {
+            Root = root;
+        }
+
+        public string Root { get; }
+
+        public static TemporaryPackage Create()
+        {
+            var root = Path.Combine(Path.GetTempPath(), "LanMountainDesktop.VersionTests", Guid.NewGuid().ToString("N"));
+            Directory.CreateDirectory(root);
+            return new TemporaryPackage(root);
+        }
+
+        public void CreateDeployment(string name, string? versionJson = null)
+        {
+            var deployment = Path.Combine(Root, name);
+            Directory.CreateDirectory(deployment);
+            File.WriteAllText(Path.Combine(deployment, "LanMountainDesktop.exe"), string.Empty);
+            File.WriteAllText(Path.Combine(deployment, ".current"), string.Empty);
+            if (versionJson is not null)
+            {
+                File.WriteAllText(Path.Combine(deployment, "version.json"), versionJson);
+            }
+        }
+
+        public void Dispose()
+        {
+            if (Directory.Exists(Root))
+            {
+                Directory.Delete(Root, recursive: true);
+            }
+        }
+    }
+}

LanMountainDesktop.Tests/DeploymentLocatorTests.cs

@@ -0,0 +1,43 @@
+using LanMountainDesktop.Launcher;
+using LanMountainDesktop.Launcher.Services;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+[Collection("LauncherDebugSettingsStore")]
+public sealed class DeploymentLocatorTests : IDisposable
+{
+    private readonly string _appRoot;
+    private readonly string _configRoot;
+
+    public DeploymentLocatorTests()
+    {
+        var testRoot = Path.Combine(Path.GetTempPath(), "LanMountainDesktop.DeploymentLocatorTests", Guid.NewGuid().ToString("N"));
+        _appRoot = Path.Combine(testRoot, "app-root");
+        _configRoot = Path.Combine(testRoot, "config");
+        Directory.CreateDirectory(_appRoot);
+        Directory.CreateDirectory(_configRoot);
+        LauncherDebugSettingsStore.ConfigBaseDirectoryOverride = _configRoot;
+    }
+
+    [Fact]
+    public void ResolveHostExecutable_WhenSavedDebugPathIsMalformed_DoesNotThrow()
+    {
+        LauncherDebugSettingsStore.Save(new LauncherDebugSettings(true, "bad\0path"));
+
+        var locator = new DeploymentLocator(_appRoot);
+        var result = locator.ResolveHostExecutable(CommandContext.FromArgs(["launch", "--debug"]));
+
+        Assert.NotEqual("debug_saved_custom_path", result.ResolutionSource);
+    }
+
+    public void Dispose()
+    {
+        LauncherDebugSettingsStore.ConfigBaseDirectoryOverride = null;
+        var testRoot = Directory.GetParent(_appRoot)?.FullName;
+        if (!string.IsNullOrWhiteSpace(testRoot) && Directory.Exists(testRoot))
+        {
+            Directory.Delete(testRoot, recursive: true);
+        }
+    }
+}

LanMountainDesktop.Tests/HostLaunchPlanBuilderTests.cs

@@ -0,0 +1,100 @@
+using LanMountainDesktop.Launcher;
+using LanMountainDesktop.Launcher.Services;
+using LanMountainDesktop.Shared.Contracts.Launcher;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+public sealed class HostLaunchPlanBuilderTests : IDisposable
+{
+    private readonly string _testRoot;
+
+    public HostLaunchPlanBuilderTests()
+    {
+        _testRoot = Path.Combine(
+            Path.GetTempPath(),
+            "LanMountainDesktop.HostLaunchPlanTests",
+            Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(_testRoot);
+    }
+
+    [Fact]
+    public void Build_UsesPackageRootAsWorkingDirectory_ForPublishedDeployment()
+    {
+        var packageRoot = Path.Combine(_testRoot, "package-root");
+        var deployment = CreateDeployment(packageRoot, "app-0.8.5.7");
+        var resultPath = Path.Combine(_testRoot, "launcher-result.json");
+        var context = CommandContext.FromArgs(
+        [
+            "launch",
+            "--app-root", packageRoot,
+            "--result", resultPath,
+            "--launch-source", "postinstall",
+            "--custom-host-arg", "custom-value"
+        ]);
+        var locator = new DeploymentLocator(packageRoot);
+        var resolution = locator.ResolveHostExecutable(context);
+
+        var plan = HostLaunchPlanBuilder.Build(context, locator, resolution);
+
+        Assert.Equal(Path.GetFullPath(packageRoot), plan.PackageRoot);
+        Assert.Equal(Path.GetFullPath(packageRoot), plan.WorkingDirectory);
+        Assert.Equal(Path.Combine(deployment, GetExecutableName()), plan.HostPath);
+        Assert.Contains("--launch-source", plan.Arguments);
+        Assert.Contains("postinstall", plan.Arguments);
+        Assert.Contains("--custom-host-arg", plan.Arguments);
+        Assert.Contains("custom-value", plan.Arguments);
+        Assert.DoesNotContain("--app-root", plan.Arguments);
+        Assert.DoesNotContain(packageRoot, plan.Arguments);
+        Assert.DoesNotContain("--result", plan.Arguments);
+        Assert.DoesNotContain(resultPath, plan.Arguments);
+        Assert.Contains($"--{LauncherIpcConstants.PackageRootEnvVar}={Path.GetFullPath(packageRoot)}", plan.Arguments);
+    }
+
+    [Fact]
+    public void Build_KeepsPathsWithSpacesAsSingleArgumentListTokens()
+    {
+        var packageRoot = Path.Combine(_testRoot, "package root with spaces");
+        CreateDeployment(packageRoot, "app-0.8.5.7");
+        var context = CommandContext.FromArgs(["launch", "--app-root", packageRoot]);
+        var locator = new DeploymentLocator(packageRoot);
+        var resolution = locator.ResolveHostExecutable(context);
+
+        var plan = HostLaunchPlanBuilder.Build(context, locator, resolution);
+
+        var packageRootArgument = $"--{LauncherIpcConstants.PackageRootEnvVar}={Path.GetFullPath(packageRoot)}";
+        Assert.Contains(packageRootArgument, plan.Arguments);
+        Assert.Equal(Path.GetFullPath(packageRoot), plan.EnvironmentVariables[LauncherIpcConstants.PackageRootEnvVar]);
+        Assert.DoesNotContain(plan.Arguments, argument => argument.StartsWith("\"", StringComparison.Ordinal));
+        Assert.Equal(Path.GetFullPath(packageRoot), plan.WorkingDirectory);
+    }
+
+    private static string CreateDeployment(string packageRoot, string deploymentName)
+    {
+        var deployment = Path.Combine(packageRoot, deploymentName);
+        Directory.CreateDirectory(deployment);
+        File.WriteAllText(Path.Combine(deployment, GetExecutableName()), string.Empty);
+        File.WriteAllText(Path.Combine(deployment, ".current"), string.Empty);
+        File.WriteAllText(
+            Path.Combine(deployment, "version.json"),
+            """
+            {"Version":"0.8.5.7","Codename":"Administrate"}
+            """);
+        return deployment;
+    }
+
+    private static string GetExecutableName()
+    {
+        return OperatingSystem.IsWindows()
+            ? "LanMountainDesktop.exe"
+            : "LanMountainDesktop";
+    }
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_testRoot))
+        {
+            Directory.Delete(_testRoot, recursive: true);
+        }
+    }
+}

LanMountainDesktop.Tests/HostShutdownGateTests.cs

@@ -0,0 +1,48 @@
+using LanMountainDesktop.Services;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+public sealed class HostShutdownGateTests
+{
+    [Fact]
+    public void Submit_WhenFirstExitRequest_AcceptsAndRecordsExit()
+    {
+        var gate = new HostShutdownGate();
+
+        var submission = gate.Submit(HostShutdownMode.Exit);
+
+        Assert.True(submission.Accepted);
+        Assert.True(submission.IsFirstSubmission);
+        Assert.Equal(HostShutdownMode.Exit, submission.EffectiveMode);
+        Assert.True(gate.IsShutdownRequested);
+        Assert.Equal(HostShutdownMode.Exit, gate.EffectiveMode);
+    }
+
+    [Fact]
+    public void Submit_WhenDuplicateSameMode_AcceptsButDoesNotExecuteAgain()
+    {
+        var gate = new HostShutdownGate();
+        gate.Submit(HostShutdownMode.Exit);
+
+        var duplicate = gate.Submit(HostShutdownMode.Exit);
+
+        Assert.True(duplicate.Accepted);
+        Assert.False(duplicate.IsFirstSubmission);
+        Assert.Equal(HostShutdownMode.Exit, duplicate.EffectiveMode);
+    }
+
+    [Fact]
+    public void Submit_WhenExitArrivesAfterRestart_DoesNotOverwriteRestart()
+    {
+        var gate = new HostShutdownGate();
+        gate.Submit(HostShutdownMode.Restart);
+
+        var conflictingExit = gate.Submit(HostShutdownMode.Exit);
+
+        Assert.False(conflictingExit.Accepted);
+        Assert.False(conflictingExit.IsFirstSubmission);
+        Assert.Equal(HostShutdownMode.Restart, conflictingExit.EffectiveMode);
+        Assert.Equal(HostShutdownMode.Restart, gate.EffectiveMode);
+    }
+}

LanMountainDesktop.Tests/LauncherCoordinatorRegistryTests.cs

@@ -0,0 +1,126 @@
+using System.Text.Json.Nodes;
+using LanMountainDesktop.Launcher.Models;
+using LanMountainDesktop.Launcher.Services;
+using LanMountainDesktop.Shared.Contracts.Launcher;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+public sealed class LauncherCoordinatorRegistryTests
+{
+    [Fact]
+    public void TryReserveCoordinator_WhenActiveCoordinatorExists_ReturnsActiveAttempt()
+    {
+        using var temp = TemporaryAttemptState.Create();
+        var firstRegistry = new StartupAttemptRegistry(temp.StatePath);
+        var secondRegistry = new StartupAttemptRegistry(temp.StatePath);
+
+        Assert.True(firstRegistry.TryReserveCoordinator(
+            "normal",
+            "Foreground",
+            "pipe-a",
+            out var firstAttempt,
+            out var firstActive));
+        Assert.Null(firstActive);
+
+        Assert.False(secondRegistry.TryReserveCoordinator(
+            "normal",
+            "Foreground",
+            "pipe-b",
+            out _,
+            out var secondActive));
+
+        Assert.NotNull(secondActive);
+        Assert.Equal(firstAttempt.AttemptId, secondActive.AttemptId);
+        Assert.Equal("pipe-a", secondActive.CoordinatorPipeName);
+        Assert.Equal(Environment.ProcessId, secondActive.CoordinatorPid);
+    }
+
+    [Fact]
+    public void TryReserveCoordinator_WhenHeartbeatIsStale_TakesOverAttempt()
+    {
+        using var temp = TemporaryAttemptState.Create();
+        var firstRegistry = new StartupAttemptRegistry(temp.StatePath);
+        var secondRegistry = new StartupAttemptRegistry(temp.StatePath);
+
+        Assert.True(firstRegistry.TryReserveCoordinator(
+            "normal",
+            "Foreground",
+            "pipe-a",
+            out var firstAttempt,
+            out _));
+        temp.SetHeartbeat(DateTimeOffset.UtcNow.AddSeconds(-30));
+
+        Assert.True(secondRegistry.TryReserveCoordinator(
+            "normal",
+            "Foreground",
+            "pipe-b",
+            out var reservedAttempt,
+            out var activeAttempt));
+
+        Assert.Null(activeAttempt);
+        Assert.Equal(firstAttempt.AttemptId, reservedAttempt.AttemptId);
+        Assert.Equal("pipe-b", reservedAttempt.CoordinatorPipeName);
+    }
+
+    [Fact]
+    public void AssignOwnedHostProcess_ClearsReservedBeforeHostStart()
+    {
+        using var temp = TemporaryAttemptState.Create();
+        var registry = new StartupAttemptRegistry(temp.StatePath);
+
+        Assert.True(registry.TryReserveCoordinator(
+            "normal",
+            "Foreground",
+            "pipe-a",
+            out var reservedAttempt,
+            out _));
+        Assert.True(reservedAttempt.ReservedBeforeHostStart);
+
+        var assignedAttempt = registry.AssignOwnedHostProcess(
+            Environment.ProcessId,
+            StartupStage.Initializing,
+            "host assigned");
+
+        Assert.Equal(Environment.ProcessId, assignedAttempt.HostPid);
+        Assert.False(assignedAttempt.ReservedBeforeHostStart);
+    }
+
+    private sealed class TemporaryAttemptState : IDisposable
+    {
+        private TemporaryAttemptState(string directory)
+        {
+            Directory = directory;
+            StatePath = Path.Combine(directory, "startup-attempt.json");
+        }
+
+        public string Directory { get; }
+
+        public string StatePath { get; }
+
+        public static TemporaryAttemptState Create()
+        {
+            var directory = Path.Combine(
+                Path.GetTempPath(),
+                "LanMountainDesktop.LauncherCoordinatorTests",
+                Guid.NewGuid().ToString("N"));
+            System.IO.Directory.CreateDirectory(directory);
+            return new TemporaryAttemptState(directory);
+        }
+
+        public void SetHeartbeat(DateTimeOffset heartbeatAtUtc)
+        {
+            var node = JsonNode.Parse(File.ReadAllText(StatePath))!.AsObject();
+            node["heartbeatAtUtc"] = heartbeatAtUtc.ToString("O");
+            File.WriteAllText(StatePath, node.ToJsonString());
+        }
+
+        public void Dispose()
+        {
+            if (System.IO.Directory.Exists(Directory))
+            {
+                System.IO.Directory.Delete(Directory, recursive: true);
+            }
+        }
+    }
+}

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);
+        }
+    }
+}

LanMountainDesktop.Tests/StartupVisualPreferencesTests.cs

@@ -0,0 +1,57 @@
+using LanMountainDesktop.Shared.Contracts.Launcher;
+using Xunit;
+
+namespace LanMountainDesktop.Tests;
+
+public sealed class StartupVisualPreferencesTests
+{
+    [Fact]
+    public void FromFlags_WhenSlideEnabled_DisablesFadeAndUsesSlideMode()
+    {
+        var preferences = StartupVisualPreferencesResolver.FromFlags(
+            enableFadeTransition: true,
+            enableSlideTransition: true);
+
+        Assert.False(preferences.EnableFadeTransition);
+        Assert.True(preferences.EnableSlideTransition);
+        Assert.Equal(StartupVisualMode.SlideSplash, preferences.Mode);
+    }
+
+    [Fact]
+    public void FromFlags_WhenFadeDisabledAndSlideDisabled_UsesStaticSplashMode()
+    {
+        var preferences = StartupVisualPreferencesResolver.FromFlags(
+            enableFadeTransition: false,
+            enableSlideTransition: false);
+
+        Assert.False(preferences.EnableFadeTransition);
+        Assert.False(preferences.EnableSlideTransition);
+        Assert.Equal(StartupVisualMode.StaticSplash, preferences.Mode);
+    }
+
+    [Fact]
+    public void Resolve_WhenFadeSettingMissing_DefaultsToFadeEnabled()
+    {
+        var tempDirectory = Path.Combine(Path.GetTempPath(), "LanMountainDesktop.StartupVisualTests", Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(tempDirectory);
+        var settingsPath = Path.Combine(tempDirectory, "settings.json");
+        File.WriteAllText(settingsPath, """
+        {
+          "enableSlideTransition": false
+        }
+        """);
+
+        try
+        {
+            var preferences = StartupVisualPreferencesResolver.Resolve(settingsPath);
+
+            Assert.True(preferences.EnableFadeTransition);
+            Assert.False(preferences.EnableSlideTransition);
+            Assert.Equal(StartupVisualMode.Fade, preferences.Mode);
+        }
+        finally
+        {
+            Directory.Delete(tempDirectory, recursive: true);
+        }
+    }
+}

LanMountainDesktop/App.axaml.cs

@@ -56,6 +56,7 @@ public partial class App : Application
     private readonly LocalizationService _localizationService = new();
     private readonly FontFamilyService _fontFamilyService = new();
     private readonly IHostApplicationLifecycle _hostApplicationLifecycle = new HostApplicationLifecycleService();
+    private readonly HostShutdownGate _shutdownGate = new();
     private readonly IDetachedComponentLibraryWindowService _detachedComponentLibraryWindowService = new DetachedComponentLibraryWindowService();
     private readonly ILocationService _locationService = HostLocationServiceProvider.GetOrCreate();
     private readonly DateTimeOffset _startupAt = DateTimeOffset.UtcNow;
@@ -71,9 +72,11 @@ public partial class App : Application
     private ShutdownIntent _shutdownIntent;
 
     private DesktopTrayService? _desktopTrayService;
+    private DispatcherTimer? _shellRecoveryTimer;
     private PluginRuntimeService? _pluginRuntimeService;
     private MainWindow? _mainWindow;
     private TransparentOverlayWindow? _transparentOverlayWindow;
+    private FusedDesktopComponentLibraryWindow? _fusedComponentLibraryWindow;
     private bool _mainWindowClosed;
     private bool _uiUnhandledExceptionHooked;
     private DesktopShellHost? _desktopShellHost;
@@ -82,6 +85,7 @@ public partial class App : Application
     private LoadingStateReporter? _loadingStateReporter;
     private bool _singleInstanceReleased;
     private int _forcedExitScheduled;
+    private volatile bool _desktopShellInitializationStarted;
     private bool _mainWindowOpened;
     private bool _trayInitialized;
     private readonly object _launcherProgressLock = new();
@@ -106,6 +110,7 @@ public partial class App : Application
     public IHostApplicationLifecycle HostApplicationLifecycle => _hostApplicationLifecycle;
     internal ISettingsWindowService? SettingsWindowService => _settingsWindowService;
     internal INotificationService? NotificationService => _notificationService;
+    internal bool IsShutdownInProgress => _shutdownGate.IsShutdownRequested || _shutdownIntent != ShutdownIntent.None;
     internal RestartPresentationMode GetCurrentRestartPresentationMode()
     {
         return _desktopShellState switch
@@ -118,6 +123,14 @@ public partial class App : Application
 
     internal void OpenIndependentSettingsModule(string source, string? pageTag = null)
     {
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info(
+                "SettingsFacade",
+                $"Settings open ignored because shutdown is in progress. Source='{source}'; PageTag='{pageTag ?? "<default>"}'.");
+            return;
+        }
+
         EnsureSettingsWindowService();
         AppLogger.Info(
             "SettingsFacade",
@@ -172,6 +185,7 @@ public partial class App : Application
         RegisterUiUnhandledExceptionGuard();
         LinuxDesktopEntryInstaller.EnsureInstalled();
         InitializePublicIpc();
+        CurrentSingleInstanceService?.StartActivationListener(ActivateMainWindow);
         _ = InitializeLauncherIpcAsync();
         DesktopBootstrap.InitializeApplication(this, InitializeDesktopShell);
 
@@ -312,6 +326,7 @@ public partial class App : Application
 
     private void InitializeDesktopShell()
     {
+        _desktopShellInitializationStarted = true;
         _desktopShellHost ??= new DesktopShellHost(
             InitializePluginRuntime,
             InitializeTrayIcon,
@@ -347,11 +362,23 @@ public partial class App : Application
 
     private void OnTrayShowDesktopClick(object? sender, EventArgs e)
     {
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info("DesktopShell", "Tray Open Desktop ignored because shutdown is in progress.");
+            return;
+        }
+
         RestoreOrCreateMainWindow(showSingleInstanceNotice: false, source: "TrayMenu");
     }
 
     private void OnTrayRestartClick(object? sender, EventArgs e)
     {
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info("HostLifecycle", "Tray Restart ignored because shutdown is already in progress.");
+            return;
+        }
+
         _ = _hostApplicationLifecycle.TryRestart(new HostApplicationLifecycleRequest(
             Source: "TrayMenu",
             Reason: "User selected Restart App from the tray menu."));
@@ -361,6 +388,13 @@ public partial class App : Application
     {
         _ = sender;
         _ = e;
+
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info("SettingsFacade", "Tray Settings ignored because shutdown is in progress.");
+            return;
+        }
+
         OpenIndependentSettingsModule("TrayMenu");
     }
 
@@ -368,28 +402,52 @@ public partial class App : Application
     {
         _ = sender;
         _ = e;
+
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info("FusedDesktop", "Tray Component Library ignored because shutdown is in progress.");
+            return;
+        }
         
         if (!OperatingSystem.IsWindows())
         {
             AppLogger.Warn("FusedDesktop", "Fused desktop is only supported on Windows.");
             return;
         }
-
-        FusedDesktopManagerServiceFactory.GetOrCreate().EnterEditMode();
-        
-        // 纭繚閫忔槑瑕嗙洊灞傜獥鍙ｅ瓨鍦ㄥ苟鏄剧ず
-        EnsureTransparentOverlayWindow();
         
         Dispatcher.UIThread.Post(() =>
         {
+            if (IsShutdownInProgress)
+            {
+                AppLogger.Info("FusedDesktop", "Deferred Component Library open ignored because shutdown is in progress.");
+                return;
+            }
+
             try
             {
+                if (_fusedComponentLibraryWindow is { } existingWindow)
+                {
+                    if (!existingWindow.IsVisible)
+                    {
+                        existingWindow.Show();
+                    }
+
+                    existingWindow.Activate();
+                    return;
+                }
+
+                var fusedDesktopManager = FusedDesktopManagerServiceFactory.GetOrCreate();
+                fusedDesktopManager.EnterEditMode();
+
+                // 纭繚閫忔槑瑕嗙洊灞傜獥鍙ｅ瓨鍦ㄥ苟鏄剧ず
+                EnsureTransparentOverlayWindow();
                 if (_transparentOverlayWindow is not null && !_transparentOverlayWindow.IsVisible)
                 {
                     _transparentOverlayWindow.Show();
                 }
                 
                 var window = new FusedDesktopComponentLibraryWindow();
+                _fusedComponentLibraryWindow = window;
                 
                 if (_transparentOverlayWindow is not null)
                 {
@@ -405,7 +463,11 @@ public partial class App : Application
                     }
                     
                     // 璁╃鐞嗗櫒鏍规嵁宸插瓨鍌ㄧ殑鏈€鏂板揩鐓ч噸寤虹敓鎴愭墍鏈夊疄浣撳皬缁勪欢
-                    FusedDesktopManagerServiceFactory.GetOrCreate().ExitEditMode();
+                    fusedDesktopManager.ExitEditMode();
+                    if (ReferenceEquals(_fusedComponentLibraryWindow, s))
+                    {
+                        _fusedComponentLibraryWindow = null;
+                    }
                 };
 
                 window.Show();
@@ -414,6 +476,25 @@ public partial class App : Application
             catch (Exception ex)
             {
                 AppLogger.Warn("FusedDesktop", "Failed to open fused desktop component library.", ex);
+                try
+                {
+                    _transparentOverlayWindow?.SaveLayoutAndHide();
+                }
+                catch (Exception overlayEx)
+                {
+                    AppLogger.Warn("FusedDesktop", "Failed to hide fused desktop overlay after library open failure.", overlayEx);
+                }
+
+                try
+                {
+                    FusedDesktopManagerServiceFactory.GetOrCreate().ExitEditMode();
+                }
+                catch (Exception exitEx)
+                {
+                    AppLogger.Warn("FusedDesktop", "Failed to exit edit mode after library open failure.", exitEx);
+                }
+
+                _fusedComponentLibraryWindow = null;
             }
         }, DispatcherPriority.Send);
     }
@@ -478,6 +559,7 @@ public partial class App : Application
     private void InitializeTrayIcon()
     {
         EnsureDesktopTrayService();
+        _desktopTrayService?.StartWatchdog();
         _trayInitialized = _desktopTrayService?.EnsureReady("Startup") == true;
         if (_trayInitialized)
         {
@@ -525,14 +607,67 @@ public partial class App : Application
             OnTrayRestartClick,
             OnTrayExitClick);
         _desktopTrayService.StateChanged += OnTrayAvailabilityStateChanged;
+        _desktopTrayService.StartWatchdog();
+        EnsureShellRecoveryWatchdog();
+    }
+
+    private void EnsureShellRecoveryWatchdog()
+    {
+        _shellRecoveryTimer ??= new DispatcherTimer(
+            TimeSpan.FromSeconds(10),
+            DispatcherPriority.Background,
+            OnShellRecoveryWatchdogTick);
+
+        if (!_shellRecoveryTimer.IsEnabled)
+        {
+            _shellRecoveryTimer.Start();
+        }
+    }
+
+    private void StopShellRecoveryWatchdog()
+    {
+        if (_shellRecoveryTimer?.IsEnabled == true)
+        {
+            _shellRecoveryTimer.Stop();
+        }
+    }
+
+    private void OnShellRecoveryWatchdogTick(object? sender, EventArgs e)
+    {
+        _ = sender;
+        _ = e;
+
+        if (_shutdownIntent != ShutdownIntent.None)
+        {
+            return;
+        }
+
+        EnsureTrayReady("ShellRecoveryWatchdog");
+
+        if (!ShouldShowMainWindowInTaskbar())
+        {
+            return;
+        }
+
+        if (_desktopShellState != DesktopShellState.ForegroundDesktop)
+        {
+            EnsureTaskbarEntry("ShellRecoveryWatchdog");
+            return;
+        }
+
+        if (_mainWindow is not null && _mainWindow.IsVisible && !_mainWindow.ShowInTaskbar)
+        {
+            _mainWindow.ShowInTaskbar = true;
+        }
     }
 
     private bool EnsureTrayReady(string reason)
     {
         EnsureDesktopTrayService();
+        var wasReady = _trayInitialized;
         var ready = _desktopTrayService?.EnsureReady(reason) == true;
         _trayInitialized = ready;
-        if (ready)
+        if (ready && !wasReady)
         {
             ReportStartupProgress(StartupStage.TrayReady, 75, "Tray ready.");
         }
@@ -544,9 +679,25 @@ public partial class App : Application
     {
         _trayInitialized = state == TrayAvailabilityState.Ready;
 
-        if (state == TrayAvailabilityState.Failed && _desktopShellState == DesktopShellState.TrayOnly)
+        if (state != TrayAvailabilityState.Failed)
+        {
+            return;
+        }
+
+        if (_desktopShellState == DesktopShellState.TrayOnly)
         {
             RestoreOrCreateMainWindow(showSingleInstanceNotice: false, source: "TrayAvailabilityFailed");
+            return;
+        }
+
+        var foregroundVisible = _mainWindow?.IsVisible == true &&
+                                _mainWindow.WindowState != WindowState.Minimized;
+        var taskbarUsable = BuildPublicTaskbarStatus().IsUsable;
+        if (!foregroundVisible &&
+            !taskbarUsable &&
+            (_desktopTrayService?.ConsecutiveRecoveryFailures ?? 0) >= 3)
+        {
+            RestoreOrCreateMainWindow(showSingleInstanceNotice: false, source: "TrayAvailabilityRepeatedFailure");
         }
     }
 
@@ -653,10 +804,16 @@ public partial class App : Application
         Resources["AppFontFamily"] = fontFamily;
     }
 
-    private void ActivateMainWindow()
+    internal void ActivateMainWindow()
     {
         AppLogger.Info("SingleInstance", $"Activation callback received. Pid={Environment.ProcessId}.");
 
+        if (!_desktopShellInitializationStarted && _mainWindow is null)
+        {
+            AppLogger.Info("SingleInstance", "Activation acknowledged while desktop shell is still initializing.");
+            return;
+        }
+
         try
         {
             var restored = Dispatcher.UIThread.CheckAccess()
@@ -667,7 +824,8 @@ public partial class App : Application
 
             if (!restored)
             {
-                throw new InvalidOperationException("Main window restore failed in activation callback.");
+                AppLogger.Warn("SingleInstance", "Activation callback could not restore the main window yet.");
+                return;
             }
 
             AppLogger.Info("SingleInstance", "Activation callback completed successfully.");
@@ -675,12 +833,17 @@ public partial class App : Application
         catch (Exception ex)
         {
             AppLogger.Warn("SingleInstance", "Activation callback failed while restoring the desktop shell.", ex);
-            throw;
         }
     }
 
     private void RestoreOrCreateMainWindow(bool showSingleInstanceNotice, string source)
     {
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info("DesktopShell", $"Restore ignored because shutdown is in progress. Source='{source}'.");
+            return;
+        }
+
         Dispatcher.UIThread.Post(() =>
         {
             _ = RestoreOrCreateMainWindowCore(showSingleInstanceNotice, source);
@@ -689,6 +852,12 @@ public partial class App : Application
 
     private bool RestoreOrCreateMainWindowCore(bool showSingleInstanceNotice, string source)
     {
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info("DesktopShell", $"Restore skipped because shutdown is in progress. Source='{source}'.");
+            return false;
+        }
+
         if (ApplicationLifetime is not IClassicDesktopStyleApplicationLifetime desktop)
         {
             AppLogger.Warn("DesktopShell", $"Restore skipped because desktop lifetime is unavailable. Source='{source}'.");
@@ -719,7 +888,10 @@ public partial class App : Application
                 mainWindow.WindowState = WindowState.Normal;
             }
 
-            if (mainWindow.WindowState != WindowState.FullScreen)
+            mainWindow.EnsureForegroundWindowLayout();
+
+            if (mainWindow.ShouldUseFullscreenWindow() &&
+                mainWindow.WindowState != WindowState.FullScreen)
             {
                 mainWindow.WindowState = WindowState.FullScreen;
             }
@@ -733,7 +905,6 @@ public partial class App : Application
                 mainWindow.PlayEnterAnimation();
             }, DispatcherPriority.Background);
 
-            _desktopTrayService?.StopWatchdog();
             SetDesktopShellState(DesktopShellState.ForegroundDesktop, $"Restore:{source}");
             AppLogger.Info(
                 "DesktopShell",
@@ -765,6 +936,62 @@ public partial class App : Application
         }
     }
 
+    internal bool TrySubmitShutdown(HostShutdownMode mode, HostApplicationLifecycleRequest? request)
+    {
+        if (ApplicationLifetime is not IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            AppLogger.Warn(
+                "HostLifecycle",
+                $"Shutdown request ignored because desktop lifetime is unavailable. Mode='{mode}'; Source='{request?.Source ?? "Unknown"}'.");
+            return false;
+        }
+
+        return Dispatcher.UIThread.CheckAccess()
+            ? TrySubmitShutdownCore(mode, request, desktop)
+            : Dispatcher.UIThread.InvokeAsync(
+                () => TrySubmitShutdownCore(mode, request, desktop),
+                DispatcherPriority.Send).GetAwaiter().GetResult();
+    }
+
+    private bool TrySubmitShutdownCore(
+        HostShutdownMode mode,
+        HostApplicationLifecycleRequest? request,
+        IClassicDesktopStyleApplicationLifetime desktop)
+    {
+        var source = request?.Source ?? "Unknown";
+        var submission = _shutdownGate.Submit(mode);
+        if (!submission.IsFirstSubmission)
+        {
+            AppLogger.Warn(
+                "HostLifecycle",
+                $"Shutdown request ignored because shutdown is already in progress. Requested='{submission.RequestedMode}'; Effective='{submission.EffectiveMode}'; Source='{source}'.");
+            return submission.Accepted;
+        }
+
+        _shutdownIntent = mode == HostShutdownMode.Restart
+            ? ShutdownIntent.RestartRequested
+            : ShutdownIntent.ExitRequested;
+        AppLogger.Info(
+            "DesktopShell",
+            $"Shutdown committed. Intent='{_shutdownIntent}'; Source='{source}'; Reason='{request?.Reason ?? string.Empty}'; CurrentShellState='{_desktopShellState}'.");
+
+        ScheduleForcedProcessTermination($"ShutdownRequest:{source}");
+        StopShellRecoveryWatchdog();
+        PerformExitCleanup();
+        ReleaseSingleInstanceAfterExit($"ShutdownRequest:{source}");
+
+        try
+        {
+            desktop.Shutdown();
+            return true;
+        }
+        catch (Exception ex)
+        {
+            AppLogger.Warn("HostLifecycle", $"Desktop lifetime shutdown failed. Source='{source}'.", ex);
+            return true;
+        }
+    }
+
     internal void PrepareForShutdown(bool isRestart, string source)
     {
         void Mark()
@@ -861,6 +1088,23 @@ public partial class App : Application
             {
                 RefreshFusedDesktopMenuItemVisibility();
             }
+
+            var showInTaskbarChanged =
+                refreshAll ||
+                changedKeys.Contains(nameof(AppSettingsSnapshot.ShowInTaskbar), StringComparer.OrdinalIgnoreCase);
+
+            if (showInTaskbarChanged)
+            {
+                EnsureTrayReady("SettingsChanged");
+                if (ShouldShowMainWindowInTaskbar())
+                {
+                    EnsureTaskbarEntry("SettingsChanged");
+                }
+                else if (_mainWindow is not null && _mainWindow.IsVisible)
+                {
+                    _mainWindow.ShowInTaskbar = false;
+                }
+            }
         }, DispatcherPriority.Background);
     }
 
@@ -977,6 +1221,7 @@ public partial class App : Application
         }
 
         _exitCleanupCompleted = true;
+        StopShellRecoveryWatchdog();
         _settingsFacade.Settings.Changed -= OnSettingsChanged;
         _appearanceThemeService.Changed -= OnAppearanceThemeChanged;
 
@@ -1032,6 +1277,30 @@ public partial class App : Application
             disposableRegistry.Dispose();
         }
 
+        if (_fusedComponentLibraryWindow is not null)
+        {
+            try
+            {
+                _fusedComponentLibraryWindow.Close();
+            }
+            catch (Exception ex)
+            {
+                AppLogger.Warn("FusedDesktop", "Failed to close fused desktop component library during shutdown.", ex);
+            }
+            finally
+            {
+                _fusedComponentLibraryWindow = null;
+                try
+                {
+                    FusedDesktopManagerServiceFactory.GetOrCreate().ExitEditMode();
+                }
+                catch (Exception ex)
+                {
+                    AppLogger.Warn("FusedDesktop", "Failed to exit fused desktop edit mode during shutdown.", ex);
+                }
+            }
+        }
+
         if (_transparentOverlayWindow is not null)
         {
             try
@@ -1155,7 +1424,6 @@ public partial class App : Application
             case RestartPresentationMode.Minimized:
                 mainWindow.ShowInTaskbar = true;
                 mainWindow.WindowState = WindowState.Minimized;
-                _desktopTrayService?.StopWatchdog();
                 SetDesktopShellState(DesktopShellState.MinimizedToTaskbar, "StartupRestartPresentation");
                 ReportStartupProgressSync(StartupStage.BackgroundReady, 95, "Background ready.");
                 return true;
@@ -1297,6 +1565,24 @@ public partial class App : Application
     {
         try
         {
+            if (ShouldShowMainWindowInTaskbar())
+            {
+                EnsureTrayReady($"TaskbarBackground:{source}");
+                mainWindow.ShowInTaskbar = true;
+                if (!mainWindow.IsVisible)
+                {
+                    mainWindow.Show();
+                }
+
+                mainWindow.WindowState = WindowState.Minimized;
+                SetDesktopShellState(DesktopShellState.MinimizedToTaskbar, source);
+                ReportStartupProgress(StartupStage.BackgroundReady, 95, "Background ready via taskbar.");
+                AppLogger.Info(
+                    "DesktopShell",
+                    $"Main window minimized to taskbar because taskbar entry is enabled. Source='{source}'.");
+                return;
+            }
+
             if (!EnsureTrayReady($"HideToTray:{source}"))
             {
                 RecoverFromTrayUnavailable(mainWindow, source);
@@ -1305,7 +1591,6 @@ public partial class App : Application
 
             mainWindow.ShowInTaskbar = false;
             mainWindow.Hide();
-            _desktopTrayService?.StartWatchdog();
             SetDesktopShellState(DesktopShellState.TrayOnly, source);
             ReportStartupProgress(StartupStage.BackgroundReady, 95, "Background ready.");
             AppLogger.Info(
@@ -1342,7 +1627,6 @@ public partial class App : Application
             }
 
             mainWindow.WindowState = WindowState.Minimized;
-            _desktopTrayService?.StopWatchdog();
             SetDesktopShellState(DesktopShellState.MinimizedToTaskbar, $"TrayFallbackTaskbar:{source}");
             ReportStartupProgress(StartupStage.BackgroundReady, 95, "Background ready via taskbar fallback.");
             return;
@@ -1359,7 +1643,10 @@ public partial class App : Application
             mainWindow.WindowState = WindowState.Normal;
         }
 
-        if (mainWindow.WindowState != WindowState.FullScreen)
+        mainWindow.EnsureForegroundWindowLayout();
+
+        if (mainWindow.ShouldUseFullscreenWindow() &&
+            mainWindow.WindowState != WindowState.FullScreen)
         {
             mainWindow.WindowState = WindowState.FullScreen;
         }
@@ -1367,7 +1654,6 @@ public partial class App : Application
         mainWindow.Activate();
         mainWindow.Topmost = true;
         mainWindow.Topmost = false;
-        _desktopTrayService?.StopWatchdog();
         SetDesktopShellState(DesktopShellState.ForegroundDesktop, $"TrayFallbackForeground:{source}");
         ReportStartupProgress(StartupStage.DesktopVisible, 100, "Desktop restored because tray was unavailable.");
     }
@@ -1377,6 +1663,54 @@ public partial class App : Application
         return _settingsFacade.Settings.LoadSnapshot<AppSettingsSnapshot>(SettingsScope.App).ShowInTaskbar;
     }
 
+    private bool EnsureTaskbarEntry(string source)
+    {
+        if (IsShutdownInProgress)
+        {
+            AppLogger.Info("DesktopShell", $"Taskbar repair skipped because shutdown is in progress. Source='{source}'.");
+            return false;
+        }
+
+        if (!ShouldShowMainWindowInTaskbar())
+        {
+            return false;
+        }
+
+        if (ApplicationLifetime is not IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            AppLogger.Warn("DesktopShell", $"Taskbar repair skipped because desktop lifetime is unavailable. Source='{source}'.");
+            return false;
+        }
+
+        try
+        {
+            var mainWindow = GetOrCreateMainWindow(desktop, $"TaskbarRepair:{source}");
+            mainWindow.ShowInTaskbar = true;
+
+            if (!mainWindow.IsVisible)
+            {
+                mainWindow.Show();
+            }
+
+            if (_desktopShellState != DesktopShellState.ForegroundDesktop)
+            {
+                mainWindow.WindowState = WindowState.Minimized;
+                SetDesktopShellState(DesktopShellState.MinimizedToTaskbar, $"TaskbarRepair:{source}");
+                ReportStartupProgress(StartupStage.BackgroundReady, 95, "Background ready via taskbar repair.");
+            }
+
+            AppLogger.Info(
+                "DesktopShell",
+                $"Taskbar entry ensured. Source='{source}'; IsVisible={mainWindow.IsVisible}; ShowInTaskbar={mainWindow.ShowInTaskbar}; WindowState='{mainWindow.WindowState}'.");
+            return true;
+        }
+        catch (Exception ex)
+        {
+            AppLogger.Warn("DesktopShell", $"Failed to ensure taskbar entry. Source='{source}'.", ex);
+            return false;
+        }
+    }
+
     private void SetDesktopShellState(DesktopShellState state, string source)
     {
         if (_desktopShellState == state)
@@ -1428,7 +1762,100 @@ public partial class App : Application
 
     internal bool TryActivateMainWindowFromExternalIpc(string source)
     {
-        return RestoreOrCreateMainWindowCore(showSingleInstanceNotice: false, source);
+        return TryActivateMainWindowWithStatusFromExternalIpc(source).Accepted;
+    }
+
+    internal PublicShellActivationResult TryActivateMainWindowWithStatusFromExternalIpc(string source)
+    {
+        if (!_desktopShellInitializationStarted && _mainWindow is null)
+        {
+            return new PublicShellActivationResult(
+                false,
+                "startup_pending",
+                "Desktop process is running, but the shell has not started yet.",
+                GetPublicShellStatus());
+        }
+
+        var restored = RestoreOrCreateMainWindowCore(showSingleInstanceNotice: false, source);
+        var status = GetPublicShellStatus();
+        if (restored)
+        {
+            return new PublicShellActivationResult(true, "activated", "Desktop window activation was requested.", status);
+        }
+
+        if (IsShutdownInProgress)
+        {
+            return new PublicShellActivationResult(false, "shutdown_in_progress", "Desktop is shutting down.", status);
+        }
+
+        var code = status.PublicIpcReady && (!status.MainWindowCreated || !status.MainWindowOpened)
+            ? "startup_pending"
+            : status.PublicIpcReady && !status.DesktopVisible
+                ? "shell_not_ready"
+                : "activation_failed";
+        var message = code switch
+        {
+            "startup_pending" => "Desktop process is running, but the shell is still creating the main window.",
+            "shell_not_ready" => "Desktop process is running, but the shell is not ready for activation yet.",
+            _ => "Desktop window activation failed."
+        };
+        return new PublicShellActivationResult(false, code, message, status);
+    }
+
+    internal PublicTrayStatus EnsureTrayReadyFromExternalIpc(string source)
+    {
+        EnsureTrayReady($"ExternalIpc:{source}");
+        return BuildPublicTrayStatus();
+    }
+
+    internal PublicTaskbarStatus EnsureTaskbarEntryFromExternalIpc(string source)
+    {
+        EnsureTaskbarEntry($"ExternalIpc:{source}");
+        return BuildPublicTaskbarStatus();
+    }
+
+    internal PublicShellStatus GetPublicShellStatus()
+    {
+        return new PublicShellStatus(
+            Environment.ProcessId,
+            _startupAt,
+            _launchSource,
+            _desktopShellState.ToString(),
+            _mainWindow is not null && !_mainWindowClosed,
+            _mainWindow?.IsVisible == true,
+            _mainWindowOpened,
+            _mainWindow?.IsVisible == true && _mainWindow.WindowState != WindowState.Minimized,
+            _publicIpcHostService is not null,
+            BuildPublicTrayStatus(),
+            BuildPublicTaskbarStatus());
+    }
+
+    private PublicTrayStatus BuildPublicTrayStatus()
+    {
+        return new PublicTrayStatus(
+            _desktopTrayService?.State.ToString() ?? TrayAvailabilityState.Unavailable.ToString(),
+            _desktopTrayService?.IsReady == true,
+            _desktopTrayService?.HasIcon == true,
+            _desktopTrayService?.HasMenu == true,
+            _desktopTrayService?.IsVisible == true,
+            _desktopTrayService?.ConsecutiveRecoveryFailures ?? 0);
+    }
+
+    private PublicTaskbarStatus BuildPublicTaskbarStatus()
+    {
+        var requested = ShouldShowMainWindowInTaskbar();
+        var mainWindowExists = _mainWindow is not null && !_mainWindowClosed;
+        var showInTaskbar = _mainWindow?.ShowInTaskbar == true;
+        var visible = _mainWindow?.IsVisible == true;
+        var minimized = _mainWindow?.WindowState == WindowState.Minimized;
+
+        return new PublicTaskbarStatus(
+            requested,
+            mainWindowExists,
+            showInTaskbar,
+            visible,
+            minimized,
+            requested && mainWindowExists && showInTaskbar && visible);
     }
 
     private void InitializePublicIpc()

LanMountainDesktop/LanMountainDesktop.csproj

@@ -90,8 +90,8 @@
       <AppVersion>$(Version)</AppVersion>
       <AppCodename>Administrate</AppCodename>
     </PropertyGroup>
-    <Exec Command="powershell -ExecutionPolicy Bypass -File $(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1 -OutputPath '$(VersionFilePath)' -Version '$(AppVersion)' -Codename '$(AppCodename)'" Condition="'$(OS)' == 'Windows_NT'" />
-    <Exec Command="pwsh -ExecutionPolicy Bypass -File $(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1 -OutputPath '$(VersionFilePath)' -Version '$(AppVersion)' -Codename '$(AppCodename)'" Condition="'$(OS)' != 'Windows_NT'" />
+    <Exec Command="powershell -ExecutionPolicy Bypass -File &quot;$(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1&quot; -OutputPath &quot;$(VersionFilePath)&quot; -Version &quot;$(AppVersion)&quot; -Codename &quot;$(AppCodename)&quot;" Condition="'$(OS)' == 'Windows_NT'" />
+    <Exec Command="pwsh -ExecutionPolicy Bypass -File &quot;$(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1&quot; -OutputPath &quot;$(VersionFilePath)&quot; -Version &quot;$(AppVersion)&quot; -Codename &quot;$(AppCodename)&quot;" Condition="'$(OS)' != 'Windows_NT'" />
   </Target>
 
   <!-- 发布时也生成版本信息文件 -->
@@ -101,7 +101,7 @@
       <AppVersion>$(Version)</AppVersion>
       <AppCodename>Administrate</AppCodename>
     </PropertyGroup>
-    <Exec Command="powershell -ExecutionPolicy Bypass -File $(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1 -OutputPath '$(VersionFilePath)' -Version '$(AppVersion)' -Codename '$(AppCodename)'" Condition="'$(OS)' == 'Windows_NT'" />
-    <Exec Command="pwsh -ExecutionPolicy Bypass -File $(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1 -OutputPath '$(VersionFilePath)' -Version '$(AppVersion)' -Codename '$(AppCodename)'" Condition="'$(OS)' != 'Windows_NT'" />
+    <Exec Command="powershell -ExecutionPolicy Bypass -File &quot;$(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1&quot; -OutputPath &quot;$(VersionFilePath)&quot; -Version &quot;$(AppVersion)&quot; -Codename &quot;$(AppCodename)&quot;" Condition="'$(OS)' == 'Windows_NT'" />
+    <Exec Command="pwsh -ExecutionPolicy Bypass -File &quot;$(MSBuildProjectDirectory)\..\scripts\Generate-VersionFile.ps1&quot; -OutputPath &quot;$(VersionFilePath)&quot; -Version &quot;$(AppVersion)&quot; -Codename &quot;$(AppCodename)&quot;" Condition="'$(OS)' != 'Windows_NT'" />
   </Target>
 </Project>

LanMountainDesktop/Models/AppSettingsSnapshot.cs

@@ -152,6 +152,8 @@ public sealed class AppSettingsSnapshot
 
     public bool EnableThreeFingerSwipe { get; set; } = false;
 
+    public bool EnableFadeTransition { get; set; } = true;
+
     public bool EnableSlideTransition { get; set; } = false;
 
     public bool ShowInTaskbar { get; set; } = false;

LanMountainDesktop/Program.cs

@@ -77,6 +77,16 @@ public sealed class Program
             StartupRenderMode = renderMode;
             AppLogger.Info("Startup", $"Resolved render mode '{renderMode}'.");
             App.CurrentSingleInstanceService = singleInstance;
+            singleInstance.StartActivationListener(() =>
+            {
+                if (Avalonia.Application.Current is App app)
+                {
+                    app.ActivateMainWindow();
+                    return;
+                }
+
+                AppLogger.Info("SingleInstance", "Activation acknowledged before Avalonia App was ready.");
+            });
             BuildAvaloniaApp(renderMode).StartWithClassicDesktopLifetime(args);
             AppLogger.Info("Startup", "Application exited normally.");
         }

LanMountainDesktop/Services/DesktopTrayService.cs

@@ -34,6 +34,7 @@ internal sealed class DesktopTrayService : IDisposable
     private NativeMenuItem? _restartMenuItem;
     private NativeMenuItem? _exitMenuItem;
     private int _consecutiveRecoveryFailures;
+    private bool _disposed;
 
     public DesktopTrayService(
         Application application,
@@ -63,6 +64,14 @@ internal sealed class DesktopTrayService : IDisposable
 
     public bool IsReady => State == TrayAvailabilityState.Ready;
 
+    public bool HasIcon => _trayIcon?.Icon is not null;
+
+    public bool HasMenu => _trayIcon?.Menu is not null;
+
+    public bool IsVisible => _trayIcon?.IsVisible == true;
+
+    public int ConsecutiveRecoveryFailures => _consecutiveRecoveryFailures;
+
     public event Action<TrayAvailabilityState>? StateChanged;
 
     public bool EnsureReady(string reason)
@@ -105,6 +114,7 @@ internal sealed class DesktopTrayService : IDisposable
 
     public void Dispose()
     {
+        _disposed = true;
         StopWatchdog();
 
         try
@@ -118,6 +128,27 @@ internal sealed class DesktopTrayService : IDisposable
         {
         }
 
+        try
+        {
+            TrayIcon.SetIcons(_application, []);
+        }
+        catch
+        {
+        }
+
+        try
+        {
+            if (_trayIcon is IDisposable disposable)
+            {
+                disposable.Dispose();
+            }
+        }
+        catch
+        {
+        }
+
+        _trayIcon = null;
+
         SetState(TrayAvailabilityState.Unavailable, "Dispose");
     }
 
@@ -126,7 +157,7 @@ internal sealed class DesktopTrayService : IDisposable
         _ = sender;
         _ = e;
 
-        if (State == TrayAvailabilityState.Unavailable || State == TrayAvailabilityState.Failed)
+        if (_disposed || State == TrayAvailabilityState.Unavailable)
         {
             return;
         }
@@ -256,6 +287,11 @@ internal sealed class DesktopTrayService : IDisposable
     {
         if (State == state)
         {
+            if (state == TrayAvailabilityState.Failed)
+            {
+                StateChanged?.Invoke(state);
+            }
+
             return;
         }
 

LanMountainDesktop/Services/ExternalIpc/PublicShellControlService.cs

@@ -7,6 +7,15 @@ namespace LanMountainDesktop.Services.ExternalIpc;
 
 internal sealed class PublicShellControlService : IPublicShellControlService
 {
+    public Task<PublicShellStatus> GetShellStatusAsync()
+    {
+        return Dispatcher.UIThread.InvokeAsync(() =>
+        {
+            return (Application.Current as App)?.GetPublicShellStatus()
+                ?? CreateUnavailableStatus();
+        }).GetTask();
+    }
+
     public Task<bool> ActivateMainWindowAsync()
     {
         return Dispatcher.UIThread.InvokeAsync(() =>
@@ -15,6 +24,37 @@ internal sealed class PublicShellControlService : IPublicShellControlService
         }).GetTask();
     }
 
+    public Task<PublicShellActivationResult> ActivateMainWindowWithStatusAsync()
+    {
+        return Dispatcher.UIThread.InvokeAsync(() =>
+        {
+            return (Application.Current as App)?.TryActivateMainWindowWithStatusFromExternalIpc("PublicIpc")
+                ?? new PublicShellActivationResult(
+                    false,
+                    "app_unavailable",
+                    "Application instance is not available.",
+                    CreateUnavailableStatus());
+        }).GetTask();
+    }
+
+    public Task<PublicTrayStatus> EnsureTrayReadyAsync()
+    {
+        return Dispatcher.UIThread.InvokeAsync(() =>
+        {
+            return (Application.Current as App)?.EnsureTrayReadyFromExternalIpc("PublicIpc")
+                ?? new PublicTrayStatus("Unavailable", false, false, false, false, 0);
+        }).GetTask();
+    }
+
+    public Task<PublicTaskbarStatus> EnsureTaskbarEntryAsync()
+    {
+        return Dispatcher.UIThread.InvokeAsync(() =>
+        {
+            return (Application.Current as App)?.EnsureTaskbarEntryFromExternalIpc("PublicIpc")
+                ?? new PublicTaskbarStatus(false, false, false, false, false, false);
+        }).GetTask();
+    }
+
     public Task<bool> OpenSettingsAsync(string? pageTag = null)
     {
         return Dispatcher.UIThread.InvokeAsync(() =>
@@ -44,4 +84,20 @@ internal sealed class PublicShellControlService : IPublicShellControlService
             Source: "PublicIpc",
             Reason: "External IPC requested exit.")) == true);
     }
+
+    private static PublicShellStatus CreateUnavailableStatus()
+    {
+        return new PublicShellStatus(
+            Environment.ProcessId,
+            DateTimeOffset.UtcNow,
+            "unknown",
+            "Unavailable",
+            false,
+            false,
+            false,
+            false,
+            false,
+            new PublicTrayStatus("Unavailable", false, false, false, false, 0),
+            new PublicTaskbarStatus(false, false, false, false, false, false));
+    }
 }

LanMountainDesktop/Services/HostApplicationLifecycleService.cs

@@ -23,23 +23,13 @@ public sealed class HostApplicationLifecycleService : IHostApplicationLifecycle
                 $"Exit requested. Source='{request?.Source ?? "Unknown"}'; Reason='{request?.Reason ?? string.Empty}'.");
 
             app = Application.Current as App;
-            if (app?.ApplicationLifetime is not IClassicDesktopStyleApplicationLifetime desktop)
+            if (app is null || app.ApplicationLifetime is not IClassicDesktopStyleApplicationLifetime)
             {
                 AppLogger.Warn("HostLifecycle", "Exit request ignored because desktop lifetime is unavailable.");
                 return false;
             }
 
-            app.PrepareForShutdown(isRestart: false, request?.Source ?? "Unknown");
-            if (Dispatcher.UIThread.CheckAccess())
-            {
-                desktop.Shutdown();
-            }
-            else
-            {
-                Dispatcher.UIThread.Post(() => desktop.Shutdown(), DispatcherPriority.Send);
-            }
-
-            return true;
+            return app.TrySubmitShutdown(HostShutdownMode.Exit, request);
         }
         catch (Exception ex)
         {
@@ -55,6 +45,13 @@ public sealed class HostApplicationLifecycleService : IHostApplicationLifecycle
         try
         {
             app = Application.Current as App;
+            if (app?.IsShutdownInProgress == true)
+            {
+                AppLogger.Warn(
+                    "HostLifecycle",
+                    $"Restart request ignored because shutdown is already in progress. Source='{request?.Source ?? "Unknown"}'.");
+                return false;
+            }
 
             if (HasPendingPluginUpgrades())
             {
@@ -123,10 +120,7 @@ public sealed class HostApplicationLifecycleService : IHostApplicationLifecycle
         AppLogger.Info("HostLifecycle", $"Starting upgrade helper: {helperStartInfo.FileName} {helperStartInfo.Arguments}");
 
         Process.Start(helperStartInfo);
-
-        app?.PrepareForShutdown(isRestart: true, request?.Source ?? "Unknown");
-
-        return TryExit(request);
+        return app?.TrySubmitShutdown(HostShutdownMode.Restart, request) == true;
     }
 
     private bool TryRestartDirectly(HostApplicationLifecycleRequest? request)
@@ -143,8 +137,7 @@ public sealed class HostApplicationLifecycleService : IHostApplicationLifecycle
         }
 
         Process.Start(startInfo);
-        app?.PrepareForShutdown(isRestart: true, request?.Source ?? "Unknown");
-        var exitRequest = request is null
+        var shutdownRequest = request is null
             ? new HostApplicationLifecycleRequest(Reason: "Restart accepted.")
             : request with
             {
@@ -153,7 +146,7 @@ public sealed class HostApplicationLifecycleService : IHostApplicationLifecycle
                     : request.Reason
             };
 
-        return TryExit(exitRequest);
+        return app?.TrySubmitShutdown(HostShutdownMode.Restart, shutdownRequest) == true;
     }
 
     private static string ResolveUpgradeHelperPath()

LanMountainDesktop/Services/HostShutdownGate.cs

@@ -0,0 +1,65 @@
+namespace LanMountainDesktop.Services;
+
+internal enum HostShutdownMode
+{
+    Exit = 0,
+    Restart = 1
+}
+
+internal readonly record struct HostShutdownSubmission(
+    bool Accepted,
+    bool IsFirstSubmission,
+    HostShutdownMode EffectiveMode,
+    HostShutdownMode RequestedMode);
+
+internal sealed class HostShutdownGate
+{
+    private readonly object _gate = new();
+    private bool _submitted;
+    private HostShutdownMode _mode;
+
+    public bool IsShutdownRequested
+    {
+        get
+        {
+            lock (_gate)
+            {
+                return _submitted;
+            }
+        }
+    }
+
+    public HostShutdownMode? EffectiveMode
+    {
+        get
+        {
+            lock (_gate)
+            {
+                return _submitted ? _mode : null;
+            }
+        }
+    }
+
+    public HostShutdownSubmission Submit(HostShutdownMode requestedMode)
+    {
+        lock (_gate)
+        {
+            if (!_submitted)
+            {
+                _submitted = true;
+                _mode = requestedMode;
+                return new HostShutdownSubmission(
+                    Accepted: true,
+                    IsFirstSubmission: true,
+                    EffectiveMode: requestedMode,
+                    RequestedMode: requestedMode);
+            }
+
+            return new HostShutdownSubmission(
+                Accepted: _mode == requestedMode,
+                IsFirstSubmission: false,
+                EffectiveMode: _mode,
+                RequestedMode: requestedMode);
+        }
+    }
+}

LanMountainDesktop/Services/SingleInstanceService.cs

@@ -16,6 +16,7 @@ public sealed class SingleInstanceService : IDisposable
     private readonly Mutex _mutex;
     private readonly string _pipeName;
     private readonly CancellationTokenSource _listenCts = new();
+    private readonly ManualResetEventSlim _listenerReady = new(false);
     private bool _ownsMutex;
     private bool _disposed;
     private Task? _listenTask;
@@ -64,6 +65,7 @@ public sealed class SingleInstanceService : IDisposable
             "SingleInstance",
             $"Starting activation listener. Pipe='{_pipeName}'; Pid={Environment.ProcessId}; OwnsMutex={_ownsMutex}.");
         _listenTask = Task.Run(() => ListenForActivationAsync(onActivationRequested, _listenCts.Token));
+        _listenerReady.Wait(TimeSpan.FromMilliseconds(500));
     }
 
     public bool TryNotifyPrimaryInstance(TimeSpan timeout)
@@ -142,6 +144,7 @@ public sealed class SingleInstanceService : IDisposable
         }
 
         _listenCts.Dispose();
+        _listenerReady.Dispose();
         if (_ownsMutex)
         {
             try
@@ -170,6 +173,7 @@ public sealed class SingleInstanceService : IDisposable
                     PipeTransmissionMode.Byte,
                     PipeOptions.Asynchronous);
 
+                _listenerReady.Set();
                 await server.WaitForConnectionAsync(cancellationToken).ConfigureAwait(false);
                 var buffer = new byte[1];
                 var readBytes = await server.ReadAsync(buffer, cancellationToken).ConfigureAwait(false);

LanMountainDesktop/ViewModels/SettingsViewModels.cs

@@ -13,6 +13,7 @@ using LanMountainDesktop.PluginSdk;
 using LanMountainDesktop.Services;
 using LanMountainDesktop.Services.Settings;
 using LanMountainDesktop.Settings.Core;
+using LanMountainDesktop.Shared.Contracts.Launcher;
 
 namespace LanMountainDesktop.ViewModels;
 
@@ -201,7 +202,7 @@ public sealed partial class GeneralSettingsPageViewModel : ViewModelBase, IDispo
         SelectedRenderMode = RenderModes.FirstOrDefault(option =>
             string.Equals(option.Value, normalizedRenderMode, StringComparison.OrdinalIgnoreCase))
             ?? RenderModes[0];
-        EnableSlideTransition = appSnapshot.EnableSlideTransition;
+        ApplyTransitionPreferences(appSnapshot.EnableFadeTransition, appSnapshot.EnableSlideTransition);
         ShowInTaskbar = appSnapshot.ShowInTaskbar;
         _isInitializing = false;
 
@@ -235,9 +236,11 @@ public sealed partial class GeneralSettingsPageViewModel : ViewModelBase, IDispo
             return;
         }
 
-        if (changedKeys.Contains(nameof(AppSettingsSnapshot.EnableSlideTransition)))
+        if (changedKeys.Contains(nameof(AppSettingsSnapshot.EnableSlideTransition)) ||
+            changedKeys.Contains(nameof(AppSettingsSnapshot.EnableFadeTransition)))
         {
-            EnableSlideTransition = _settingsFacade.Settings.LoadSnapshot<AppSettingsSnapshot>(SettingsScope.App).EnableSlideTransition;
+            var snapshot = _settingsFacade.Settings.LoadSnapshot<AppSettingsSnapshot>(SettingsScope.App);
+            ApplyTransitionPreferences(snapshot.EnableFadeTransition, snapshot.EnableSlideTransition);
         }
 
         if (changedKeys.Contains(nameof(AppSettingsSnapshot.ShowInTaskbar)))
@@ -263,6 +266,9 @@ public sealed partial class GeneralSettingsPageViewModel : ViewModelBase, IDispo
     [ObservableProperty]
     private SelectionOption _selectedRenderMode = new(AppRenderingModeHelper.Default, "Default");
 
+    [ObservableProperty]
+    private bool _enableFadeTransition = true;
+
     [ObservableProperty]
     private bool _enableSlideTransition;
 
@@ -271,6 +277,12 @@ public sealed partial class GeneralSettingsPageViewModel : ViewModelBase, IDispo
 
     public bool IsSlideTransitionAvailable => System.Runtime.InteropServices.RuntimeInformation.IsOSPlatform(System.Runtime.InteropServices.OSPlatform.Windows);
 
+    public bool IsFadeTransitionToggleEnabled => !EnableSlideTransition;
+
+    public string FadeTransitionDescription => EnableSlideTransition
+        ? "滑动模式已启用，淡入淡出不可同时使用。"
+        : "启用后，启动与恢复过程使用淡入淡出效果。";
+
     [ObservableProperty]
     private string _pageTitle = string.Empty;
 
@@ -372,8 +384,22 @@ public sealed partial class GeneralSettingsPageViewModel : ViewModelBase, IDispo
 
     partial void OnEnableSlideTransitionChanged(bool value)
     {
-        if (_isInitializing) return;
-        SaveField(nameof(AppSettingsSnapshot.EnableSlideTransition), value);
+        if (_isInitializing)
+        {
+            return;
+        }
+
+        SaveTransitionPreferences(EnableFadeTransition, value);
+    }
+
+    partial void OnEnableFadeTransitionChanged(bool value)
+    {
+        if (_isInitializing)
+        {
+            return;
+        }
+
+        SaveTransitionPreferences(value, EnableSlideTransition);
     }
 
     partial void OnShowInTaskbarChanged(bool value)
@@ -394,6 +420,35 @@ public sealed partial class GeneralSettingsPageViewModel : ViewModelBase, IDispo
         _settingsFacade.Settings.SaveSnapshot(SettingsScope.App, snapshot, changedKeys: [key]);
     }
 
+    private void SaveTransitionPreferences(bool enableFadeTransition, bool enableSlideTransition)
+    {
+        var normalized = StartupVisualPreferencesResolver.FromFlags(enableFadeTransition, enableSlideTransition);
+        var snapshot = _settingsFacade.Settings.LoadSnapshot<AppSettingsSnapshot>(SettingsScope.App);
+        snapshot.EnableFadeTransition = normalized.EnableFadeTransition;
+        snapshot.EnableSlideTransition = normalized.EnableSlideTransition;
+        ApplyTransitionPreferences(normalized.EnableFadeTransition, normalized.EnableSlideTransition);
+        _settingsFacade.Settings.SaveSnapshot(
+            SettingsScope.App,
+            snapshot,
+            changedKeys:
+            [
+                nameof(AppSettingsSnapshot.EnableFadeTransition),
+                nameof(AppSettingsSnapshot.EnableSlideTransition)
+            ]);
+    }
+
+    private void ApplyTransitionPreferences(bool enableFadeTransition, bool enableSlideTransition)
+    {
+        var normalized = StartupVisualPreferencesResolver.FromFlags(enableFadeTransition, enableSlideTransition);
+        var wasInitializing = _isInitializing;
+        _isInitializing = true;
+        EnableFadeTransition = normalized.EnableFadeTransition;
+        EnableSlideTransition = normalized.EnableSlideTransition;
+        _isInitializing = wasInitializing;
+        OnPropertyChanged(nameof(IsFadeTransitionToggleEnabled));
+        OnPropertyChanged(nameof(FadeTransitionDescription));
+    }
+
     private IReadOnlyList<SelectionOption> CreateLanguageOptions()
     {
         return

LanMountainDesktop/Views/MainWindow.SettingsHardCut.Stubs.cs

@@ -79,6 +79,7 @@ public partial class MainWindow
                 string.Equals(key, nameof(AppSettingsSnapshot.UpdateDownloadSource), StringComparison.OrdinalIgnoreCase) ||
                 string.Equals(key, nameof(AppSettingsSnapshot.UpdateDownloadThreads), StringComparison.OrdinalIgnoreCase) ||
                 string.Equals(key, nameof(AppSettingsSnapshot.EnableThreeFingerSwipe), StringComparison.OrdinalIgnoreCase) ||
+                string.Equals(key, nameof(AppSettingsSnapshot.EnableFadeTransition), StringComparison.OrdinalIgnoreCase) ||
                 string.Equals(key, nameof(AppSettingsSnapshot.ShowInTaskbar), StringComparison.OrdinalIgnoreCase) ||
                 string.Equals(key, nameof(AppSettingsSnapshot.EnableSlideTransition), StringComparison.OrdinalIgnoreCase)))
             {
@@ -690,6 +691,7 @@ public partial class MainWindow
             StatusBarShadowColor = _statusBarShadowColor,
             StatusBarShadowOpacity = _statusBarShadowOpacity,
             EnableThreeFingerSwipe = existingSnapshot.EnableThreeFingerSwipe,
+            EnableFadeTransition = existingSnapshot.EnableFadeTransition,
             EnableSlideTransition = existingSnapshot.EnableSlideTransition,
             ShowInTaskbar = existingSnapshot.ShowInTaskbar,
             EnableFusedDesktop = existingSnapshot.EnableFusedDesktop,

LanMountainDesktop/Views/MainWindow.axaml.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
@@ -23,6 +24,7 @@ using LanMountainDesktop.Models;
 using LanMountainDesktop.PluginSdk;
 using LanMountainDesktop.Services;
 using LanMountainDesktop.Services.Settings;
+using LanMountainDesktop.Shared.Contracts.Launcher;
 using LanMountainDesktop.Theme;
 using LanMountainDesktop.Views.Components;
 
@@ -134,6 +136,8 @@ public partial class MainWindow : Window
     private string _gridSpacingPreset = "Relaxed";
     private bool _isSlideAnimationActive;
     private TranslateTransform? _desktopPageSlideTransform;
+    private PixelPoint? _preparedWindowTargetPosition;
+    private PixelPoint? _preparedWindowHiddenPosition;
     private string _statusBarSpacingMode = "Relaxed";
     private int _statusBarCustomSpacingPercent = 12;
     private bool _statusBarClockTransparentBackground;
@@ -862,24 +866,45 @@ public partial class MainWindow : Window
         return _desktopPageSlideTransform;
     }
 
+    internal bool ShouldUseFullscreenWindow()
+    {
+        return GetStartupVisualPreferences().Mode != StartupVisualMode.SlideSplash;
+    }
+
+    internal void EnsureForegroundWindowLayout()
+    {
+        if (!IsSlideTransitionEnabled())
+        {
+            return;
+        }
+
+        var layout = ResolveWindowAnimationLayout();
+        ApplyWindowAnimationLayout(layout);
+        Position = layout.VisiblePosition;
+    }
+
     private async void SlideOutAndMinimizeAsync()
     {
         _isSlideAnimationActive = true;
         DesktopPage.IsHitTestVisible = false;
 
-        var useSlide = IsSlideTransitionEnabled();
-        var slideTransform = GetDesktopPageSlideTransform();
+        var preferences = GetStartupVisualPreferences();
+        WindowAnimationLayout? slideLayout = null;
 
-        if (useSlide)
+        if (preferences.Mode == StartupVisualMode.SlideSplash)
         {
-            slideTransform.X = Bounds.Width;
+            slideLayout = ResolveWindowAnimationLayout();
+            ApplyWindowAnimationLayout(slideLayout.Value);
+            await AnimateWindowPositionAsync(
+                Position,
+                slideLayout.Value.HiddenPosition,
+                FluttermotionToken.Intro).ConfigureAwait(false);
+        }
+        else if (preferences.Mode == StartupVisualMode.Fade)
+        {
+            DesktopPage.Opacity = 0;
+            await Task.Delay(FluttermotionToken.Page);
         }
-
-        DesktopPage.Opacity = 0;
-
-        await Task.Delay(useSlide
-            ? FluttermotionToken.Intro
-            : FluttermotionToken.Page);
 
         if (!_isSlideAnimationActive)
         {
@@ -900,44 +925,63 @@ public partial class MainWindow : Window
             WindowState = WindowState.Minimized;
         }
 
-        slideTransform.X = 0;
         DesktopPage.Opacity = 1;
         DesktopPage.IsHitTestVisible = true;
         _isSlideAnimationActive = false;
+        if (slideLayout is { } layout)
+        {
+            Position = layout.VisiblePosition;
+        }
     }
 
     public void PrepareEnterAnimation()
     {
         _isSlideAnimationActive = false;
 
-        var useSlide = IsSlideTransitionEnabled();
-        var slideTransform = GetDesktopPageSlideTransform();
+        var preferences = GetStartupVisualPreferences();
+        _preparedWindowTargetPosition = null;
+        _preparedWindowHiddenPosition = null;
 
-        var savedTransitions = DesktopPage.Transitions;
-        DesktopPage.Transitions = null;
-
-        DesktopPage.Opacity = 0;
-
-        if (useSlide)
+        if (preferences.Mode == StartupVisualMode.SlideSplash)
         {
-            var screen = Screens.ScreenFromVisual(this);
-            var scale = screen?.Scaling ?? 1d;
-            var screenWidthDip = screen is null
-                ? 1920d
-                : screen.WorkingArea.Width / Math.Max(scale, 0.01d);
-            slideTransform.X = Bounds.Width > 0 ? Bounds.Width : screenWidthDip;
+            var layout = ResolveWindowAnimationLayout();
+            _preparedWindowTargetPosition = layout.VisiblePosition;
+            _preparedWindowHiddenPosition = layout.HiddenPosition;
+            ApplyWindowAnimationLayout(layout);
+            Position = layout.HiddenPosition;
+            DesktopPage.Opacity = 1;
+            DesktopPage.IsHitTestVisible = false;
+            _isSlideAnimationActive = true;
+            return;
         }
 
-        DesktopPage.Transitions = savedTransitions;
-        DesktopPage.IsHitTestVisible = false;
-        _isSlideAnimationActive = true;
+        if (preferences.Mode == StartupVisualMode.Fade)
+        {
+            var savedTransitions = DesktopPage.Transitions;
+            DesktopPage.Transitions = null;
+            DesktopPage.Opacity = 0;
+            DesktopPage.Transitions = savedTransitions;
+            DesktopPage.IsHitTestVisible = false;
+            _isSlideAnimationActive = true;
+            return;
+        }
+
+        DesktopPage.Opacity = 1;
+        DesktopPage.IsHitTestVisible = true;
     }
 
     public void PlayEnterAnimation()
     {
-        var slideTransform = GetDesktopPageSlideTransform();
+        var preferences = GetStartupVisualPreferences();
+        if (preferences.Mode == StartupVisualMode.SlideSplash &&
+            _preparedWindowTargetPosition is { } targetPosition &&
+            _preparedWindowHiddenPosition is { } hiddenPosition)
+        {
+            _ = PlayWindowEnterAnimationAsync(hiddenPosition, targetPosition);
+            return;
+        }
+
         DesktopPage.Opacity = 1;
-        slideTransform.X = 0;
         DesktopPage.IsHitTestVisible = true;
         _isSlideAnimationActive = false;
     }
@@ -949,10 +993,67 @@ public partial class MainWindow : Window
             return false;
         }
 
-        var snapshot = _settingsService.LoadSnapshot<AppSettingsSnapshot>(SettingsScope.App);
-        return snapshot.EnableSlideTransition;
+        return GetStartupVisualPreferences().Mode == StartupVisualMode.SlideSplash;
     }
 
+    private StartupVisualPreferences GetStartupVisualPreferences()
+    {
+        var snapshot = _settingsService.LoadSnapshot<AppSettingsSnapshot>(SettingsScope.App);
+        return StartupVisualPreferencesResolver.FromFlags(
+            snapshot.EnableFadeTransition,
+            snapshot.EnableSlideTransition);
+    }
+
+    private WindowAnimationLayout ResolveWindowAnimationLayout()
+    {
+        var screen = Screens.ScreenFromVisual(this) ?? Screens.Primary ?? Screens.All.FirstOrDefault();
+        var workingArea = screen?.WorkingArea ?? new PixelRect(0, 0, 1920, 1080);
+        var scaling = Math.Max(screen?.Scaling ?? 1d, 0.01d);
+
+        return new WindowAnimationLayout(
+            new PixelPoint(workingArea.X, workingArea.Y),
+            new PixelPoint(workingArea.X + workingArea.Width, workingArea.Y),
+            new Size(workingArea.Width / scaling, workingArea.Height / scaling));
+    }
+
+    private void ApplyWindowAnimationLayout(WindowAnimationLayout layout)
+    {
+        WindowState = WindowState.Normal;
+        Width = layout.WindowSize.Width;
+        Height = layout.WindowSize.Height;
+    }
+
+    private async Task PlayWindowEnterAnimationAsync(PixelPoint hiddenPosition, PixelPoint targetPosition)
+    {
+        Position = hiddenPosition;
+        await AnimateWindowPositionAsync(hiddenPosition, targetPosition, FluttermotionToken.Intro);
+        DesktopPage.IsHitTestVisible = true;
+        _isSlideAnimationActive = false;
+    }
+
+    private async Task AnimateWindowPositionAsync(PixelPoint from, PixelPoint to, TimeSpan duration)
+    {
+        var totalMilliseconds = Math.Max(duration.TotalMilliseconds, 1d);
+        var stopwatch = Stopwatch.StartNew();
+
+        while (stopwatch.Elapsed < duration)
+        {
+            var progress = Math.Clamp(stopwatch.Elapsed.TotalMilliseconds / totalMilliseconds, 0d, 1d);
+            var eased = 1d - Math.Pow(1d - progress, 3d);
+            var x = (int)Math.Round(from.X + ((to.X - from.X) * eased));
+            var y = (int)Math.Round(from.Y + ((to.Y - from.Y) * eased));
+            Position = new PixelPoint(x, y);
+            await Task.Delay(16).ConfigureAwait(false);
+        }
+
+        Position = to;
+    }
+
+    private readonly record struct WindowAnimationLayout(
+        PixelPoint VisiblePosition,
+        PixelPoint HiddenPosition,
+        Size WindowSize);
+
     private void OnWindowPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
     {
         if (e.Property != WindowStateProperty)
@@ -966,10 +1067,17 @@ public partial class MainWindow : Window
         if (oldState == WindowState.Minimized && newState != WindowState.Minimized)
         {
             PrepareEnterAnimation();
-            
-            if (newState != WindowState.FullScreen)
+
+            if (ShouldUseFullscreenWindow())
             {
-                WindowState = WindowState.FullScreen;
+                if (newState != WindowState.FullScreen)
+                {
+                    WindowState = WindowState.FullScreen;
+                }
+            }
+            else if (newState == WindowState.Minimized)
+            {
+                WindowState = WindowState.Normal;
             }
 
             Dispatcher.UIThread.Post(() =>
@@ -980,7 +1088,8 @@ public partial class MainWindow : Window
             return;
         }
 
-        if (newState is WindowState.Minimized or WindowState.FullScreen)
+        if (newState == WindowState.Minimized ||
+            (ShouldUseFullscreenWindow() && newState == WindowState.FullScreen))
         {
             return;
         }
@@ -999,7 +1108,10 @@ public partial class MainWindow : Window
 
             if (WindowState is not (WindowState.Minimized or WindowState.FullScreen))
             {
-                WindowState = WindowState.FullScreen;
+                if (ShouldUseFullscreenWindow())
+                {
+                    WindowState = WindowState.FullScreen;
+                }
             }
         });
     }

LanMountainDesktop/Views/SettingsPages/GeneralSettingsPage.axaml

@@ -9,7 +9,6 @@
     <ScrollViewer VerticalScrollBarVisibility="Auto">
         <StackPanel Classes="settings-page-container settings-page-animated">
 
-            <!-- 区域设置分组 -->
             <controls:IconText Icon="Globe"
                                Text="{Binding BasicHeader}"
                                Margin="0,0,0,4" />
@@ -76,7 +75,6 @@
 
             <Separator Classes="settings-separator" />
 
-            <!-- 运行时设置分组 -->
             <controls:IconText Icon="DeveloperBoard"
                                Text="{Binding RuntimeHeader}"
                                Margin="0,0,0,4" />
@@ -106,8 +104,20 @@
                 </ui:SettingsExpanderItem>
             </ui:SettingsExpander>
 
-            <ui:SettingsExpander Header="滑入滑出过渡效果"
-                                 Description="启用后，进入和退出桌面时使用滑入滑出动画（仅 Windows）"
+            <ui:SettingsExpander Header="淡入淡出效果"
+                                 Description="{Binding FadeTransitionDescription}"
+                                 IsVisible="{Binding IsSlideTransitionAvailable}">
+                <ui:SettingsExpander.IconSource>
+                    <fi:SymbolIconSource Symbol="ArrowUpload" />
+                </ui:SettingsExpander.IconSource>
+                <ui:SettingsExpander.Footer>
+                    <ToggleSwitch IsChecked="{Binding EnableFadeTransition}"
+                                  IsEnabled="{Binding IsFadeTransitionToggleEnabled}" />
+                </ui:SettingsExpander.Footer>
+            </ui:SettingsExpander>
+
+            <ui:SettingsExpander Header="启动滑入滑出效果"
+                                 Description="启用后，启动和恢复时从屏幕右侧边缘滑入或滑出，仅 Windows 可用。"
                                  IsVisible="{Binding IsSlideTransitionAvailable}">
                 <ui:SettingsExpander.IconSource>
                     <fi:SymbolIconSource Symbol="ArrowRight" />
@@ -118,7 +128,7 @@
             </ui:SettingsExpander>
 
             <ui:SettingsExpander Header="桌面主窗口在任务栏显示图标"
-                                 Description="仅控制桌面主窗口在系统任务栏中的图标显示；不会影响设置窗口，设置窗口打开时始终保留独立任务栏图标">
+                                 Description="仅控制桌面主窗口在系统任务栏中的图标显示，不影响设置窗口。">
                 <ui:SettingsExpander.IconSource>
                     <fi:SymbolIconSource Symbol="Window" />
                 </ui:SettingsExpander.IconSource>

docs/EXTERNAL_IPC_ARCHITECTURE.md

@@ -40,7 +40,7 @@ Current built-in `[IpcPublic]` contracts:
 - `IPublicAppInfoService`
   - Returns application metadata such as version, codename, process id, pipe name, and startup time.
 - `IPublicShellControlService`
-  - Allows external .NET clients to activate the shell, open settings, request restart, and request exit.
+  - Allows external .NET clients to query shell status, activate the shell, repair tray readiness, repair taskbar entry visibility, open settings, request restart, and request exit.
 - `IPublicPluginCatalogService`
   - Returns the merged public IPC catalog snapshot exposed by Host.
 
@@ -77,6 +77,8 @@ Launcher no longer depends on the previous custom named-pipe length-prefixed pro
 
 This means Splash/OOBE is now just another IPC consumer on the same base transport used by external integrators.
 
+Launcher-to-launcher de-duplication is intentionally separate from Host Public IPC. The active Launcher coordinator uses a per-user local pipe and `startup-attempt.json` heartbeat so secondary Launchers attach to the coordinator before any host process can be started twice.
+
 ## Plugin Public IPC Contribution Model
 
 Plugins can contribute new external IPC services in two ways:

docs/LAUNCHER.md

@@ -569,3 +569,7 @@ Launcher now consumes Host startup telemetry from the unified public IPC stack:
 - Launcher connects through `LanMountainDesktopIpcClient`
 
 The previous custom length-prefixed named-pipe transport is no longer the primary startup communication path.
+
+## Coordinator Guard
+
+Launcher also owns a small per-user local coordinator used only between Launcher processes. It reserves `startup-attempt.json` before host launch, publishes a heartbeat, and exposes a local coordinator pipe for secondary Launchers. A secondary Launcher must attach to that coordinator or activate the existing Host through Public IPC instead of starting another Host process. See [Launcher Coordinator](LAUNCHER_COORDINATOR.md).

docs/LAUNCHER_COORDINATOR.md

@@ -0,0 +1,31 @@
+# Launcher Coordinator
+
+LanMountainDesktop Launcher uses a per-user coordinator to prevent duplicate host startup.
+
+## Rules
+
+- A Launcher reserves `%LocalAppData%\LanMountainDesktop\.launcher\state\startup-attempt.json` before starting the host.
+- The active record stores coordinator pid, coordinator pipe name, heartbeat, host pid, Public IPC state, and shell status.
+- Only the active coordinator may start the host process.
+- Secondary Launchers attach to the coordinator and request desktop activation.
+- A coordinator is considered live while its pid exists and its heartbeat is newer than `10s`.
+- Normal launch probes Host Public IPC first; if the host is already running, Launcher activates it and exits.
+
+## Tray And Taskbar
+
+- Tray icon and tray menu are mandatory and are not controlled by user settings.
+- Tray watchdog starts with the shell and runs until process exit.
+- `ShowInTaskbar=true` affects only the main-window taskbar entry.
+- When `ShowInTaskbar=true`, background mode uses a minimized taskbar entry while keeping tray visible.
+- Pure `TrayOnly` is allowed only when `ShowInTaskbar=false` and tray is ready.
+
+## Public Shell IPC
+
+Launcher and external callers can use:
+
+- `GetShellStatusAsync()`
+- `ActivateMainWindowWithStatusAsync()`
+- `EnsureTrayReadyAsync()`
+- `EnsureTaskbarEntryAsync()`
+
+These APIs report process, shell, tray, taskbar, and activation state separately so callers do not infer health from window visibility alone.

docs/LAUNCHER_STARTUP_VISUALS.md

@@ -0,0 +1,28 @@
+# Launcher Startup Visuals
+
+This supplement records the startup rules that are shared by the launcher and the desktop host.
+
+## Timeout behavior
+
+- `30 seconds` is a soft timeout.
+- Soft timeout means `still starting`, not `failed`.
+- When the host process is alive or Public IPC is connected, Launcher keeps waiting and avoids launching another host process.
+- `120 seconds` is the hard timeout for `desktop_not_visible`.
+
+## Visual mode resolution
+
+- `EnableSlideTransition = true` resolves to `SlideSplash` and forces `EnableFadeTransition = false`.
+- `EnableSlideTransition = false` and `EnableFadeTransition = false` resolves to `StaticSplash`.
+- `EnableSlideTransition = false` and `EnableFadeTransition = true` resolves to `Fade`.
+
+## Fullscreen splash rules
+
+- Fullscreen splash uses the shared `logo_nightly.png` asset.
+- Slide splash enters from the right edge of the target screen and exits back to the right edge.
+- Static splash uses the same fullscreen black surface without motion.
+
+## Recovery rules
+
+- Closing Launcher during startup does not cancel the startup attempt.
+- Relaunching Launcher attaches to the active attempt instead of spawning a second desktop process.
+- If a host process is still alive during failure handling, Launcher offers activation or continued waiting before any retry.

scripts/Generate-VersionFile.ps1

@@ -1,15 +1,47 @@
-# 生成版本信息文件
 param(
     [Parameter(Mandatory=$true)]
     [string]$OutputPath,
-    
+
     [Parameter(Mandatory=$true)]
     [string]$Version,
-    
+
     [Parameter(Mandatory=$false)]
     [string]$Codename = "Administrate"
 )
 
+$ErrorActionPreference = "Stop"
+
+function Normalize-ArgumentValue {
+    param(
+        [Parameter(Mandatory=$true)]
+        [AllowEmptyString()]
+        [string]$Value
+    )
+
+    $trimmed = $Value.Trim()
+    if ($trimmed.Length -ge 2) {
+        $first = $trimmed[0]
+        $last = $trimmed[$trimmed.Length - 1]
+        if (($first -eq "'" -and $last -eq "'") -or ($first -eq '"' -and $last -eq '"')) {
+            return $trimmed.Substring(1, $trimmed.Length - 2).Trim()
+        }
+    }
+
+    return $trimmed
+}
+
+$OutputPath = Normalize-ArgumentValue -Value $OutputPath
+$Version = Normalize-ArgumentValue -Value $Version
+$Codename = Normalize-ArgumentValue -Value $Codename
+
+if ([string]::IsNullOrWhiteSpace($OutputPath)) {
+    throw "OutputPath is required."
+}
+
+if ([string]::IsNullOrWhiteSpace($Version)) {
+    throw "Version is required."
+}
+
 $versionInfo = @{
     Version = $Version
     Codename = $Codename
@@ -18,11 +50,15 @@ $versionInfo = @{
 $json = $versionInfo | ConvertTo-Json -Compress
 $dir = Split-Path -Parent $OutputPath
 
-if (!(Test-Path $dir)) {
+if ([string]::IsNullOrWhiteSpace($dir)) {
+    throw "OutputPath must include a directory: $OutputPath"
+}
+
+if (!(Test-Path -LiteralPath $dir)) {
     New-Item -ItemType Directory -Path $dir -Force | Out-Null
 }
 
-Set-Content -Path $OutputPath -Value $json -Encoding UTF8
+Set-Content -LiteralPath $OutputPath -Value $json -Encoding UTF8
 Write-Host "Generated version file: $OutputPath" -ForegroundColor Green
 Write-Host "  Version: $Version" -ForegroundColor Gray
 Write-Host "  Codename: $Codename" -ForegroundColor Gray