fix(launcher): close LA4 review findings

.github/workflows/headless-portability.yml

@@ -7,6 +7,7 @@ on:
       - "AcDream.slnx"
       - "src/AcDream.Platform/**"
       - "src/AcDream.Launcher.Core/**"
+      - "src/AcDream.Launcher/**"
       - "src/AcDream.Core/**"
       - "src/AcDream.Core.Net/**"
       - "src/AcDream.Content/**"
@@ -17,6 +18,7 @@ on:
       - "src/AcDream.UI.Abstractions/**"
       - "tests/AcDream.Platform.Tests/**"
       - "tests/AcDream.Launcher.Core.Tests/**"
+      - "tests/AcDream.Launcher.Tests/**"
       - "tests/AcDream.Core.Tests/**"
       - "tests/AcDream.Core.Net.Tests/**"
       - "tests/AcDream.Content.Tests/**"
@@ -33,6 +35,7 @@ on:
       - "AcDream.slnx"
       - "src/AcDream.Platform/**"
       - "src/AcDream.Launcher.Core/**"
+      - "src/AcDream.Launcher/**"
       - "src/AcDream.Core/**"
       - "src/AcDream.Core.Net/**"
       - "src/AcDream.Content/**"
@@ -43,6 +46,7 @@ on:
       - "src/AcDream.UI.Abstractions/**"
       - "tests/AcDream.Platform.Tests/**"
       - "tests/AcDream.Launcher.Core.Tests/**"
+      - "tests/AcDream.Launcher.Tests/**"
       - "tests/AcDream.Core.Tests/**"
       - "tests/AcDream.Core.Net.Tests/**"
       - "tests/AcDream.Content.Tests/**"
@@ -131,6 +135,59 @@ jobs:
           dotnet run --project src/AcDream.Headless/AcDream.Headless.csproj -c Release -- validate --config headless-k0.json
           if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
 
+  portable-launcher:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [windows-latest, ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Install .NET 10
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: "10.0.x"
+
+      - name: Build and test the portable launcher
+        shell: pwsh
+        run: |
+          dotnet build src/AcDream.Launcher/AcDream.Launcher.csproj -c Release
+          if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+          dotnet test tests/AcDream.Launcher.Tests/AcDream.Launcher.Tests.csproj -c Release
+          if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+
+      - name: Publish the self-contained Linux launcher
+        if: runner.os == 'Linux'
+        shell: pwsh
+        run: |
+          dotnet publish src/AcDream.Launcher/AcDream.Launcher.csproj `
+            -c Release `
+            -r linux-x64 `
+            -o artifacts/acdream-launcher-linux-x64
+          if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+
+      - name: Verify self-contained property and artifact execution
+        if: runner.os == 'Linux'
+        shell: bash
+        run: |
+          set -euo pipefail
+          root=artifacts/acdream-launcher-linux-x64
+          self_contained=$(dotnet msbuild \
+            src/AcDream.Launcher/AcDream.Launcher.csproj \
+            -nologo \
+            -property:RuntimeIdentifier=linux-x64 \
+            -getProperty:SelfContained | tr -d '\r\n ')
+          test "$self_contained" = true
+          test -x "$root/acdream-launcher"
+          test ! -f "$root/acdream-launcher.dll"
+          DOTNET_ROOT=/definitely-not-installed \
+          DOTNET_ROOT_X64=/definitely-not-installed \
+          DOTNET_MULTILEVEL_LOOKUP=0 \
+            "$root/acdream-launcher" --verify-publish
+
   linux-graphical:
     runs-on: ubuntu-latest
 

src/AcDream.Launcher.Core/Orchestration/ILauncherOrchestrator.cs

@@ -18,6 +18,11 @@ public interface ILauncherOrchestrator : IDisposable
 
     LauncherCapability GetLaunchCapability(LaunchMode mode);
 
+    LauncherCapability GetAccountLaunchCapability(
+        string serverName,
+        string accountName,
+        LaunchMode mode);
+
     LauncherCapability GetProbeCapability(string serverName, string accountName);
 
     void SetInstallRecord(LauncherInstallRecord? installRecord);
@@ -67,7 +72,7 @@ public interface ILauncherOrchestrator : IDisposable
     Task<LauncherSessionSnapshot> LaunchAsync(
         string serverName,
         string accountName,
-        string characterName,
+        string? characterName,
         LaunchMode mode,
         CancellationToken cancellationToken = default);
 

src/AcDream.Launcher.Core/Orchestration/LauncherExecutableSet.cs

@@ -4,20 +4,59 @@ using AcDream.Launcher.Core.Profiles;
 namespace AcDream.Launcher.Core.Orchestration;
 
 /// <summary>
-/// Host executable paths supplied by the current installation. LA10 will
-/// resolve these from the versioned <c>app/current</c> pointer; LA4 keeps the
-/// mapping injectable and host-agnostic.
+/// Resolves and validates the co-deployed graphical/headless hosts. LA10 will
+/// replace the directory lookup with its versioned-current resolver; until
+/// then a missing host disables the corresponding action instead of deferring
+/// failure until process creation.
 /// </summary>
-public sealed record LauncherExecutableSet(
-    string GraphicalHostPath,
-    string HeadlessHostPath,
-    string? WorkingDirectory = null)
+public sealed class LauncherExecutableSet
 {
+    private readonly Func<string, bool> _fileExists;
+
+    public LauncherExecutableSet(
+        string graphicalHostPath,
+        string headlessHostPath,
+        string? workingDirectory = null,
+        Func<string, bool>? fileExists = null)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(graphicalHostPath);
+        ArgumentException.ThrowIfNullOrWhiteSpace(headlessHostPath);
+        GraphicalHostPath = graphicalHostPath;
+        HeadlessHostPath = headlessHostPath;
+        WorkingDirectory = workingDirectory;
+        _fileExists = fileExists ?? File.Exists;
+    }
+
+    public string GraphicalHostPath { get; }
+
+    public string HeadlessHostPath { get; }
+
+    public string? WorkingDirectory { get; }
+
+    public LauncherCapability GetAvailability(LaunchMode mode)
+    {
+        string path = mode == LaunchMode.Headless
+            ? HeadlessHostPath
+            : GraphicalHostPath;
+        if (_fileExists(path))
+        {
+            return LauncherCapability.Available;
+        }
+
+        string host = mode == LaunchMode.Headless
+            ? "headless host"
+            : "graphical client";
+        return LauncherCapability.Unavailable(
+            $"The co-deployed {host} is missing at '{path}'. Reinstall or update "
+            + "the client before launching.");
+    }
+
     public LauncherProcessSpec CreatePlaySpec(
         LaunchMode mode,
         string configFilePath)
     {
         ArgumentException.ThrowIfNullOrWhiteSpace(configFilePath);
+        RequireAvailable(mode);
 
         return mode == LaunchMode.Headless
             ? new LauncherProcessSpec(
@@ -33,6 +72,7 @@ public sealed record LauncherExecutableSet(
     public LauncherProcessSpec CreateProbeSpec(string configFilePath)
     {
         ArgumentException.ThrowIfNullOrWhiteSpace(configFilePath);
+        RequireAvailable(LaunchMode.Headless);
         return new LauncherProcessSpec(
             HeadlessHostPath,
             ["--config", configFilePath],
@@ -49,4 +89,14 @@ public sealed record LauncherExecutableSet(
             Path.Combine(fullDirectory, "acdream-headless" + executableSuffix),
             fullDirectory);
     }
+
+    private void RequireAvailable(LaunchMode mode)
+    {
+        LauncherCapability capability = GetAvailability(mode);
+        if (!capability.IsAvailable)
+        {
+            throw new LauncherOperationException(
+                capability.Reason ?? "The selected launcher host is unavailable.");
+        }
+    }
 }

src/AcDream.Launcher.Core/Orchestration/LauncherOrchestrator.cs

@@ -99,6 +99,12 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
             return platformCapability;
         }
 
+        LauncherCapability executableCapability = _executables.GetAvailability(mode);
+        if (!executableCapability.IsAvailable)
+        {
+            return executableCapability;
+        }
+
         lock (_gate)
         {
             ThrowIfDisposed();
@@ -108,6 +114,33 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
         }
     }
 
+    public LauncherCapability GetAccountLaunchCapability(
+        string serverName,
+        string accountName,
+        LaunchMode mode)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(serverName);
+        ArgumentException.ThrowIfNullOrWhiteSpace(accountName);
+
+        LauncherCapability capability = GetLaunchCapability(mode);
+        if (!capability.IsAvailable)
+        {
+            return capability;
+        }
+
+        lock (_gate)
+        {
+            ThrowIfDisposed();
+            _ = FindAccountLocked(serverName, accountName);
+            ManagedActivity? active = FindActiveActivityLocked(serverName, accountName);
+            return active is null
+                ? LauncherCapability.Available
+                : LauncherCapability.Unavailable(
+                    $"Stop the running {active.Kind.ToString().ToLowerInvariant()} "
+                    + "for this account before starting another activity.");
+        }
+    }
+
     public LauncherCapability GetProbeCapability(string serverName, string accountName)
     {
         ArgumentException.ThrowIfNullOrWhiteSpace(serverName);
@@ -120,6 +153,13 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
             return platformCapability;
         }
 
+        LauncherCapability executableCapability =
+            _executables.GetAvailability(LaunchMode.Headless);
+        if (!executableCapability.IsAvailable)
+        {
+            return executableCapability;
+        }
+
         lock (_gate)
         {
             ThrowIfDisposed();
@@ -254,7 +294,7 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
     public Task<LauncherSessionSnapshot> LaunchAsync(
         string serverName,
         string accountName,
-        string characterName,
+        string? characterName,
         LaunchMode mode,
         CancellationToken cancellationToken = default)
     {
@@ -268,12 +308,38 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
         lock (_gate)
         {
             ThrowIfDisposed();
+            if (FindActiveActivityLocked(serverName, accountName) is not null)
+            {
+                throw new LauncherOperationException(
+                    "A session or character refresh is already running for this account.");
+            }
+
             ServerProfile server = FindServerLocked(serverName);
             AccountProfile account = FindAccountLocked(serverName, accountName);
-            CharacterProfile character = FindCharacterLocked(
-                serverName,
-                accountName,
-                characterName);
+            CharacterProfile character;
+            if (string.IsNullOrWhiteSpace(characterName))
+            {
+                if (mode != LaunchMode.GuiSelect)
+                {
+                    throw new LauncherOperationException(
+                        "Select a cached character for GUI or headless launch.");
+                }
+
+                character = new CharacterProfile
+                {
+                    Name = string.Empty,
+                    LaunchMode = LaunchMode.GuiSelect,
+                    Plugins = [],
+                    LoginCommands = [],
+                };
+            }
+            else
+            {
+                character = FindCharacterLocked(
+                    serverName,
+                    accountName,
+                    characterName);
+            }
             LauncherInstallRecord install = _installRecord
                 ?? throw new LauncherOperationException(FirstRunRequired);
 
@@ -283,7 +349,7 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
                 LauncherActivityKind.Play,
                 server.Name,
                 account.Account,
-                character.Name,
+                string.IsNullOrWhiteSpace(characterName) ? null : character.Name,
                 mode,
                 "Preparing session configuration…");
             _activities.Add(activity);
@@ -620,9 +686,12 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
 
             lock (_gate)
             {
-                request.Activity.State = LauncherActivityState.Cancelled;
-                request.Activity.Status = "Operation cancelled.";
-                request.Activity.Error = null;
+                if (!request.Activity.IsTerminal)
+                {
+                    request.Activity.State = LauncherActivityState.Cancelled;
+                    request.Activity.Status = "Operation cancelled.";
+                    request.Activity.Error = null;
+                }
             }
 
             RaiseStateChanged();
@@ -638,9 +707,12 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
                 password);
             lock (_gate)
             {
-                request.Activity.State = LauncherActivityState.Failed;
-                request.Activity.Status = message;
-                request.Activity.Error = message;
+                if (!request.Activity.IsTerminal)
+                {
+                    request.Activity.State = LauncherActivityState.Failed;
+                    request.Activity.Status = message;
+                    request.Activity.Error = message;
+                }
             }
 
             RaiseStateChanged();
@@ -681,15 +753,19 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
                         }
                         break;
                     case LauncherSessionState.Exited:
-                        activity.ExitCode = activity.Supervisor?.ExitCode;
-                        if (activity.State is not (
-                            LauncherActivityState.Failed
-                            or LauncherActivityState.Cancelled))
+                        activity.ExitCode ??= activity.Supervisor?.ExitCode;
+                        if (!activity.IsTerminal)
                         {
                             activity.State = LauncherActivityState.Exited;
-                            activity.Status = activity.ExitCode is int code
-                                ? $"Host process exited with code {code}."
-                                : "Host process exited.";
+                            activity.Status = activity.HostTerminalStatus
+                                ?? (activity.ExitCode is int code
+                                    ? $"Host process exited with code {code}."
+                                    : "Host process exited.");
+                        }
+                        else if (activity.State == LauncherActivityState.Exited
+                            && activity.HostTerminalStatus is not null)
+                        {
+                            activity.Status = activity.HostTerminalStatus;
                         }
                         break;
                 }
@@ -723,6 +799,27 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
                 return;
             }
 
+            if (activity.IsTerminal)
+            {
+                switch (statusEvent)
+                {
+                    case ExitedStatusEvent exited:
+                        activity.ExitCode ??= exited.Code;
+                        activity.HostTerminalStatus ??=
+                            $"Exited: {exited.Reason} (code {exited.Code}).";
+                        if (activity.State == LauncherActivityState.Exited)
+                        {
+                            activity.Status = activity.HostTerminalStatus;
+                        }
+                        break;
+                    case CharacterListStatusEvent roster:
+                        ApplyRosterLocked(activity, roster, updateStatus: false);
+                        break;
+                }
+
+                return;
+            }
+
             switch (statusEvent)
             {
                 case StartedStatusEvent:
@@ -762,7 +859,9 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
                 case ExitedStatusEvent exited:
                     activity.State = LauncherActivityState.Exited;
                     activity.ExitCode = exited.Code;
-                    activity.Status = $"Exited: {exited.Reason} (code {exited.Code}).";
+                    activity.HostTerminalStatus =
+                        $"Exited: {exited.Reason} (code {exited.Code}).";
+                    activity.Status = activity.HostTerminalStatus;
                     break;
                 case MalformedStatusEvent malformed:
                     activity.Error = $"Malformed host status event: {malformed.Error}";
@@ -778,7 +877,8 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
 
     private void ApplyRosterLocked(
         ManagedActivity activity,
-        CharacterListStatusEvent roster)
+        CharacterListStatusEvent roster,
+        bool updateStatus = true)
     {
         if (!string.Equals(
                 roster.AccountName,
@@ -792,19 +892,22 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
 
         try
         {
-            _profileStore.MergeRoster(
-                activity.ServerName,
-                activity.AccountName,
-                roster.Characters
-                    .Select(character => new CharacterRosterEntry(
-                        character.Id,
-                        character.Name,
-                        character.SecondsGreyedOut))
-                    .ToArray());
-            _profileStore.Save();
-            activity.Status = roster.Characters.Count == 1
-                ? "Character roster refreshed: 1 character."
-                : $"Character roster refreshed: {roster.Characters.Count} characters.";
+            _profileStore.ExecuteTransaction(() =>
+                _profileStore.MergeRoster(
+                    activity.ServerName,
+                    activity.AccountName,
+                    roster.Characters
+                        .Select(character => new CharacterRosterEntry(
+                            character.Id,
+                            character.Name,
+                            character.SecondsGreyedOut))
+                        .ToArray()));
+            if (updateStatus)
+            {
+                activity.Status = roster.Characters.Count == 1
+                    ? "Character roster refreshed: 1 character."
+                    : $"Character roster refreshed: {roster.Characters.Count} characters.";
+            }
         }
         catch (Exception ex)
         {
@@ -812,7 +915,10 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
                 "Could not save the refreshed character roster",
                 ex,
                 secret: null);
-            activity.Status = activity.Error;
+            if (updateStatus)
+            {
+                activity.Status = activity.Error;
+            }
         }
     }
 
@@ -879,8 +985,7 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
         lock (_gate)
         {
             ThrowIfDisposed();
-            mutation();
-            _profileStore.Save();
+            _profileStore.ExecuteTransaction(mutation);
         }
 
         RaiseStateChanged();
@@ -1125,6 +1230,8 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
 
         public string? Error { get; set; }
 
+        public string? HostTerminalStatus { get; set; }
+
         public ILauncherProcessSupervisor? Supervisor { get; set; }
 
         public EventHandler<LauncherSessionState>? SupervisorStateHandler { get; set; }
@@ -1140,6 +1247,8 @@ public sealed class LauncherOrchestrator : ILauncherOrchestrator
             or LauncherActivityState.Failed
             or LauncherActivityState.Cancelled);
 
+        public bool IsTerminal => !IsActive;
+
         public LauncherSessionSnapshot ToSnapshot() =>
             new(
                 SessionId,

src/AcDream.Launcher.Core/Profiles/LauncherProfileStore.cs

@@ -81,6 +81,8 @@ public sealed class LauncherProfileStore
             return false;
         }
 
+        EnsureExistingCredentialFilePermissions();
+
         LauncherProfileDocument? document;
         using (FileStream stream = File.OpenRead(FilePath))
         {
@@ -110,6 +112,7 @@ public sealed class LauncherProfileStore
                 + $"expected {CurrentVersion}.");
         }
 
+        ValidateAndNormalizeDocument(document);
         Document = document;
         return true;
     }
@@ -152,6 +155,13 @@ public sealed class LauncherProfileStore
                 JsonSerializer.Serialize(stream, Document, SerializerOptions);
             }
 
+            if (OperatingSystem.IsLinux()
+                && File.GetUnixFileMode(tempPath) != OwnerOnlyFileMode)
+            {
+                throw new IOException(
+                    "The launcher credential temp file could not be secured to mode 0600.");
+            }
+
             File.Move(tempPath, FilePath, overwrite: true);
         }
         catch
@@ -160,10 +170,6 @@ public sealed class LauncherProfileStore
             throw;
         }
 
-        if (OperatingSystem.IsLinux())
-        {
-            File.SetUnixFileMode(FilePath, OwnerOnlyFileMode);
-        }
     }
 
     /// <summary>
@@ -248,21 +254,21 @@ public sealed class LauncherProfileStore
                 throw new LauncherProfileException(
                     $"A server named '{newName}' already exists.");
             }
-
-            server.Name = newName;
         }
 
         if (newHost is not null)
         {
             ArgumentException.ThrowIfNullOrWhiteSpace(newHost);
-            server.Host = newHost;
         }
 
         if (newPort is not null)
         {
             RequireValidPort(newPort.Value);
-            server.Port = newPort.Value;
         }
+
+        server.Name = newName ?? server.Name;
+        server.Host = newHost ?? server.Host;
+        server.Port = newPort ?? server.Port;
     }
 
     public void RemoveServer(string name)
@@ -308,10 +314,10 @@ public sealed class LauncherProfileStore
                 throw new LauncherProfileException(
                     $"Account '{newAccount}' already exists on server '{serverName}'.");
             }
-
-            profile.Account = newAccount;
         }
 
+        profile.Account = newAccount ?? profile.Account;
+
         if (newPassword is not null)
         {
             profile.Password = newPassword;
@@ -345,6 +351,9 @@ public sealed class LauncherProfileStore
         IReadOnlyList<string>? loginCommands = null)
     {
         ArgumentException.ThrowIfNullOrWhiteSpace(characterName);
+        RequireValidLaunchMode(launchMode);
+        ValidateStringList(plugins, "plugin", requireUnique: true);
+        ValidateStringList(loginCommands, "login command", requireUnique: false);
         ServerProfile server = FindServerOrThrow(serverName);
         AccountProfile profile = FindAccountOrThrow(server, account);
 
@@ -393,6 +402,8 @@ public sealed class LauncherProfileStore
         AccountProfile profile = FindAccountOrThrow(server, account);
         CharacterProfile character = FindCharacterOrThrow(profile, characterName);
 
+        string? normalizedId = null;
+
         if (newName is not null)
         {
             ArgumentException.ThrowIfNullOrWhiteSpace(newName);
@@ -402,13 +413,11 @@ public sealed class LauncherProfileStore
                 throw new LauncherProfileException(
                     $"Character '{newName}' already exists on account '{account}'.");
             }
-
-            character.Name = newName;
         }
 
         if (newId is not null)
         {
-            string? normalizedId = NormalizeCharacterId(newId);
+            normalizedId = NormalizeCharacterId(newId);
             if (normalizedId is not null
                 && profile.Characters.Any(candidate =>
                     !ReferenceEquals(candidate, character)
@@ -417,7 +426,19 @@ public sealed class LauncherProfileStore
                 throw new LauncherProfileException(
                     $"Character id '{normalizedId}' already exists on account '{account}'.");
             }
+        }
 
+        if (launchMode is not null)
+        {
+            RequireValidLaunchMode(launchMode.Value);
+        }
+
+        ValidateStringList(plugins, "plugin", requireUnique: true);
+        ValidateStringList(loginCommands, "login command", requireUnique: false);
+
+        character.Name = newName ?? character.Name;
+        if (newId is not null)
+        {
             character.Id = normalizedId;
         }
 
@@ -437,6 +458,57 @@ public sealed class LauncherProfileStore
         }
     }
 
+    private void EnsureExistingCredentialFilePermissions()
+    {
+        if (!OperatingSystem.IsLinux())
+        {
+            return;
+        }
+
+        try
+        {
+            UnixFileMode mode = File.GetUnixFileMode(FilePath);
+            if (mode != OwnerOnlyFileMode)
+            {
+                File.SetUnixFileMode(FilePath, OwnerOnlyFileMode);
+                mode = File.GetUnixFileMode(FilePath);
+            }
+
+            if (mode != OwnerOnlyFileMode)
+            {
+                throw new IOException($"Mode remained {mode} after normalization.");
+            }
+        }
+        catch (Exception ex) when (ex is IOException or UnauthorizedAccessException)
+        {
+            throw new LauncherProfileException(
+                $"'{FilePath}' could not be secured to owner-only mode 0600.",
+                ex);
+        }
+    }
+
+    /// <summary>
+    /// Applies one profile mutation and its atomic file replacement as a
+    /// single in-memory/on-disk transaction. Any validation or I/O failure
+    /// restores the exact pre-mutation document, including credentials.
+    /// </summary>
+    public void ExecuteTransaction(Action mutation)
+    {
+        ArgumentNullException.ThrowIfNull(mutation);
+        LauncherProfileDocument before = CloneDocument(Document);
+        try
+        {
+            mutation();
+            ValidateAndNormalizeDocument(Document);
+            Save();
+        }
+        catch
+        {
+            Document = before;
+            throw;
+        }
+    }
+
     public void RemoveCharacter(
         string serverName,
         string account,
@@ -472,38 +544,49 @@ public sealed class LauncherProfileStore
         ServerProfile server = FindServerOrThrow(serverName);
         AccountProfile profile = FindAccountOrThrow(server, account);
 
+        var rosterIds = new HashSet<uint>();
+        var rosterNames = new HashSet<string>(StringComparer.Ordinal);
+        foreach (CharacterRosterEntry entry in roster)
+        {
+            if (entry.Id == 0)
+            {
+                throw new LauncherProfileException("A roster character id cannot be zero.");
+            }
+
+            ArgumentException.ThrowIfNullOrWhiteSpace(entry.Name);
+            if (!rosterIds.Add(entry.Id) || !rosterNames.Add(entry.Name))
+            {
+                throw new LauncherProfileException(
+                    "The reported character roster contains a duplicate id or name.");
+            }
+        }
+
         foreach (CharacterRosterEntry entry in roster)
         {
             string idText = CharacterIdFormat.ToHexString(entry.Id);
 
-            // Normalize BOTH sides through TryParse/ToHexString rather
-            // than a raw string compare (Campaign LA plan §LA3 review
-            // finding F10): a stored id that round-trips to the same
-            // uint (different case, or — before this fix — no "0x"
-            // prefix) must match even though its text isn't byte-
-            // identical to the canonical form this method itself always
-            // writes.
-            CharacterProfile? existing = profile.Characters.Find(
-                character => CharacterIdFormat.TryParse(character.Id, out uint existingId)
-                    && existingId == entry.Id);
-
-            // Defensive fallback for a row whose id is missing OR
-            // unparseable (e.g. a hand-edited id with no "0x" prefix,
-            // which TryParse now rejects outright) — match by name
-            // instead so a later merge self-heals the id into the
-            // canonical form rather than creating a permanent duplicate
-            // row.
-            existing ??= profile.Characters.Find(
-                character => !CharacterIdFormat.TryParse(character.Id, out _)
-                    && string.Equals(
-                        character.Name,
-                        entry.Name,
-                        StringComparison.Ordinal));
+            CharacterProfile[] matches = profile.Characters
+                .Where(character =>
+                    (CharacterIdFormat.TryParse(character.Id, out uint existingId)
+                        && existingId == entry.Id)
+                    || string.Equals(character.Name, entry.Name, StringComparison.Ordinal))
+                .ToArray();
+            CharacterProfile? existing = matches.FirstOrDefault(character =>
+                    CharacterIdFormat.TryParse(character.Id, out uint existingId)
+                    && existingId == entry.Id)
+                ?? matches.FirstOrDefault();
 
             if (existing is not null)
             {
                 existing.Id = idText;
                 existing.Name = entry.Name;
+                foreach (CharacterProfile duplicate in matches)
+                {
+                    if (!ReferenceEquals(duplicate, existing))
+                    {
+                        profile.Characters.Remove(duplicate);
+                    }
+                }
                 continue;
             }
 
@@ -583,6 +666,192 @@ public sealed class LauncherProfileStore
         && CharacterIdFormat.TryParse(right, out uint rightId)
         && leftId == rightId;
 
+    private static LauncherProfileDocument CloneDocument(
+        LauncherProfileDocument source) =>
+        new()
+        {
+            Version = source.Version,
+            Servers = source.Servers.Select(server => new ServerProfile
+            {
+                Name = server.Name,
+                Host = server.Host,
+                Port = server.Port,
+                Accounts = server.Accounts.Select(account => new AccountProfile
+                {
+                    Account = account.Account,
+                    Password = account.Password,
+                    Characters = account.Characters.Select(character => new CharacterProfile
+                    {
+                        Name = character.Name,
+                        Id = character.Id,
+                        LaunchMode = character.LaunchMode,
+                        Plugins = [.. character.Plugins],
+                        LoginCommands = [.. character.LoginCommands],
+                    }).ToList(),
+                }).ToList(),
+            }).ToList(),
+        };
+
+    private static void ValidateAndNormalizeDocument(LauncherProfileDocument document)
+    {
+        if (document.Servers is null)
+        {
+            throw new LauncherProfileException("The servers collection cannot be null.");
+        }
+
+        var serverNames = new HashSet<string>(StringComparer.Ordinal);
+        var normalizedIds = new List<(CharacterProfile Character, uint Id)>();
+        foreach (ServerProfile? server in document.Servers)
+        {
+            if (server is null)
+            {
+                throw new LauncherProfileException("A server entry cannot be null.");
+            }
+
+            RequireLoadedText(server.Name, "server name");
+            RequireLoadedText(server.Host, $"host for server '{server.Name}'");
+            RequireValidPort(server.Port);
+            if (!serverNames.Add(server.Name))
+            {
+                throw new LauncherProfileException(
+                    $"A server named '{server.Name}' appears more than once.");
+            }
+
+            if (server.Accounts is null)
+            {
+                throw new LauncherProfileException(
+                    $"The accounts collection for server '{server.Name}' cannot be null.");
+            }
+
+            var accountNames = new HashSet<string>(StringComparer.Ordinal);
+            foreach (AccountProfile? account in server.Accounts)
+            {
+                if (account is null)
+                {
+                    throw new LauncherProfileException(
+                        $"A null account appears under server '{server.Name}'.");
+                }
+
+                RequireLoadedText(account.Account, "account name");
+                if (account.Password is null)
+                {
+                    throw new LauncherProfileException(
+                        $"Password for account '{account.Account}' cannot be null.");
+                }
+
+                if (!accountNames.Add(account.Account))
+                {
+                    throw new LauncherProfileException(
+                        $"Account '{account.Account}' appears more than once on server '{server.Name}'.");
+                }
+
+                if (account.Characters is null)
+                {
+                    throw new LauncherProfileException(
+                        $"The characters collection for account '{account.Account}' cannot be null.");
+                }
+
+                var characterNames = new HashSet<string>(StringComparer.Ordinal);
+                var characterIds = new HashSet<uint>();
+                foreach (CharacterProfile? character in account.Characters)
+                {
+                    if (character is null)
+                    {
+                        throw new LauncherProfileException(
+                            $"A null character appears under account '{account.Account}'.");
+                    }
+
+                    RequireLoadedText(character.Name, "character name");
+                    if (!characterNames.Add(character.Name))
+                    {
+                        throw new LauncherProfileException(
+                            $"Character '{character.Name}' appears more than once on account '{account.Account}'.");
+                    }
+
+                    RequireValidLaunchMode(character.LaunchMode);
+                    if (character.Id is not null)
+                    {
+                        if (!CharacterIdFormat.TryParse(character.Id, out uint id) || id == 0)
+                        {
+                            throw new LauncherProfileException(
+                                $"Character '{character.Name}' has an invalid id '{character.Id}'.");
+                        }
+
+                        if (!characterIds.Add(id))
+                        {
+                            throw new LauncherProfileException(
+                                $"Character id '{character.Id}' appears more than once on account '{account.Account}'.");
+                        }
+
+                        normalizedIds.Add((character, id));
+                    }
+
+                    if (character.Plugins is null || character.LoginCommands is null)
+                    {
+                        throw new LauncherProfileException(
+                            $"Character '{character.Name}' has a null settings collection.");
+                    }
+
+                    ValidateStringList(character.Plugins, "plugin", requireUnique: true);
+                    ValidateStringList(
+                        character.LoginCommands,
+                        "login command",
+                        requireUnique: false);
+                }
+            }
+        }
+
+        foreach ((CharacterProfile character, uint id) in normalizedIds)
+        {
+            character.Id = CharacterIdFormat.ToHexString(id);
+        }
+    }
+
+    private static void ValidateStringList(
+        IReadOnlyList<string>? values,
+        string valueName,
+        bool requireUnique)
+    {
+        if (values is null)
+        {
+            return;
+        }
+
+        HashSet<string>? seen = requireUnique
+            ? new HashSet<string>(StringComparer.Ordinal)
+            : null;
+        foreach (string? value in values)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+            {
+                throw new LauncherProfileException(
+                    $"A {valueName} cannot be null or whitespace.");
+            }
+
+            if (seen is not null && !seen.Add(value))
+            {
+                throw new LauncherProfileException(
+                    $"The {valueName} '{value}' appears more than once.");
+            }
+        }
+    }
+
+    private static void RequireLoadedText(string? value, string field)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            throw new LauncherProfileException($"The {field} cannot be null or whitespace.");
+        }
+    }
+
+    private static void RequireValidLaunchMode(LaunchMode mode)
+    {
+        if (!Enum.IsDefined(mode))
+        {
+            throw new LauncherProfileException($"Launch mode '{mode}' is not supported.");
+        }
+    }
+
     private static void RequireValidPort(int port)
     {
         if (port is < 1 or > 65535)

src/AcDream.Launcher/AcDream.Launcher.csproj

@@ -10,6 +10,7 @@
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <PublishSingleFile>true</PublishSingleFile>
     <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
+    <SelfContained Condition="'$(RuntimeIdentifier)' == 'linux-x64'">true</SelfContained>
   </PropertyGroup>
 
   <ItemGroup>

src/AcDream.Launcher/MainWindow.axaml

@@ -85,7 +85,8 @@
             <Button Content="+ Account" Command="{Binding AddAccountCommand}" />
             <Button Content="+ Character" Command="{Binding AddCharacterCommand}" />
           </StackPanel>
-          <TreeView Grid.Row="2"
+          <TreeView x:Name="ProfilesTree"
+                    Grid.Row="2"
                     ItemsSource="{Binding Servers}"
                     SelectedItem="{Binding SelectedNode, Mode=TwoWay}">
             <TreeView.DataTemplates>
@@ -136,8 +137,11 @@
                 <TextBlock Text="Passwords stay only in launcher-profiles.json and are handed to children through standard input."
                            TextWrapping="Wrap" />
                 <StackPanel Orientation="Horizontal" Spacing="8">
-                  <Button Content="Refresh characters"
+                  <Button Content="Open character select"
                           Classes="primary"
+                          AutomationProperties.Name="Open character select for account"
+                          Command="{Binding LaunchAccountGuiSelectCommand}" />
+                  <Button Content="Refresh characters"
                           Command="{Binding RefreshCharactersCommand}" />
                   <Button Content="Add cached character"
                           Command="{Binding AddCharacterCommand}" />
@@ -145,6 +149,9 @@
                 <TextBlock Text="{Binding ProbeDisabledReason}"
                            Classes="muted"
                            TextWrapping="Wrap" />
+                <TextBlock Text="{Binding AccountGuiSelectDisabledReason}"
+                           Classes="muted"
+                           TextWrapping="Wrap" />
               </StackPanel>
             </Border>
 
@@ -192,11 +199,11 @@
                   <TextBlock Text="{Binding GuiLaunchDisabledReason}"
                              Classes="muted"
                              TextWrapping="Wrap"
-                             IsVisible="{Binding ShowLinuxGraphicalNotice}" />
+                             IsVisible="{Binding ShowGuiLaunchDisabledReason}" />
                   <TextBlock Text="{Binding HeadlessLaunchDisabledReason}"
                              Classes="muted"
                              TextWrapping="Wrap"
-                             IsVisible="{Binding IsFirstRunRequired}" />
+                             IsVisible="{Binding ShowHeadlessLaunchDisabledReason}" />
                 </StackPanel>
               </Border>
             </StackPanel>
@@ -260,6 +267,10 @@
     <Border Grid.RowSpan="4"
             ZIndex="20"
             Background="#C010151D"
+            Focusable="True"
+            KeyboardNavigation.TabNavigation="Cycle"
+            KeyDown="OnModalKeyDown"
+            AutomationProperties.Name="Profile editor modal dialog"
             IsVisible="{Binding EditorDialog.IsOpen}">
       <Border Classes="card"
               Width="480"
@@ -271,26 +282,36 @@
 
           <StackPanel IsVisible="{Binding EditorDialog.IsServerEditor}" Spacing="6">
             <TextBlock Text="Name" />
-            <TextBox Text="{Binding EditorDialog.Name, Mode=TwoWay}" />
+            <TextBox x:Name="ServerNameTextBox"
+                     AutomationProperties.Name="Server name"
+                     Text="{Binding EditorDialog.Name, Mode=TwoWay}" />
             <TextBlock Text="Host" />
-            <TextBox Text="{Binding EditorDialog.Host, Mode=TwoWay}" />
+            <TextBox AutomationProperties.Name="Server host"
+                     Text="{Binding EditorDialog.Host, Mode=TwoWay}" />
             <TextBlock Text="Port" />
-            <TextBox Text="{Binding EditorDialog.Port, Mode=TwoWay}" />
+            <TextBox AutomationProperties.Name="Server port"
+                     Text="{Binding EditorDialog.Port, Mode=TwoWay}" />
           </StackPanel>
 
           <StackPanel IsVisible="{Binding EditorDialog.IsAccountEditor}" Spacing="6">
             <TextBlock Text="Account name" />
-            <TextBox Text="{Binding EditorDialog.Name, Mode=TwoWay}" />
+            <TextBox x:Name="AccountNameTextBox"
+                     AutomationProperties.Name="Account name"
+                     Text="{Binding EditorDialog.Name, Mode=TwoWay}" />
             <TextBlock Text="Password" />
             <TextBox Text="{Binding EditorDialog.Password, Mode=TwoWay}"
+                     AutomationProperties.Name="Account password"
                      PasswordChar="●" />
           </StackPanel>
 
           <StackPanel IsVisible="{Binding EditorDialog.IsCharacterEditor}" Spacing="6">
             <TextBlock Text="Character name" />
-            <TextBox Text="{Binding EditorDialog.Name, Mode=TwoWay}" />
+            <TextBox x:Name="CharacterNameTextBox"
+                     AutomationProperties.Name="Character name"
+                     Text="{Binding EditorDialog.Name, Mode=TwoWay}" />
             <TextBlock Text="Character id (optional, 0x-prefixed)" />
-            <TextBox Text="{Binding EditorDialog.CharacterId, Mode=TwoWay}" />
+            <TextBox AutomationProperties.Name="Character id"
+                     Text="{Binding EditorDialog.CharacterId, Mode=TwoWay}" />
           </StackPanel>
 
           <TextBlock Text="{Binding EditorDialog.Error}"
@@ -298,9 +319,15 @@
                      IsVisible="{Binding EditorDialog.HasError}"
                      TextWrapping="Wrap" />
           <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Spacing="8">
-            <Button Content="Cancel" Command="{Binding EditorDialog.CancelCommand}" />
-            <Button Content="{Binding EditorDialog.SubmitText}"
+            <Button Content="Cancel"
+                    IsCancel="True"
+                    AutomationProperties.Name="Cancel profile change"
+                    Command="{Binding EditorDialog.CancelCommand}" />
+            <Button x:Name="EditorSubmitButton"
+                    Content="{Binding EditorDialog.SubmitText}"
                     Classes="primary"
+                    IsDefault="True"
+                    AutomationProperties.Name="Confirm profile change"
                     Command="{Binding EditorDialog.SubmitCommand}" />
           </StackPanel>
         </StackPanel>
@@ -310,6 +337,10 @@
     <Border Grid.RowSpan="4"
             ZIndex="30"
             Background="#C010151D"
+            Focusable="True"
+            KeyboardNavigation.TabNavigation="Cycle"
+            KeyDown="OnModalKeyDown"
+            AutomationProperties.Name="First-run setup modal dialog"
             IsVisible="{Binding FirstRunWizardShell.IsOpen}">
       <Border Classes="card" Width="560" HorizontalAlignment="Center" VerticalAlignment="Center">
         <StackPanel Spacing="12">
@@ -318,8 +349,12 @@
           <Border Background="#24344B" Padding="10" CornerRadius="5">
             <TextBlock Text="{Binding FirstRunWizardShell.Status}" TextWrapping="Wrap" />
           </Border>
-          <Button Content="Close"
+          <Button x:Name="FirstRunCloseButton"
+                  Content="Close"
                   HorizontalAlignment="Right"
+                  IsCancel="True"
+                  IsDefault="True"
+                  AutomationProperties.Name="Close first-run setup"
                   Command="{Binding FirstRunWizardShell.CloseCommand}" />
         </StackPanel>
       </Border>
@@ -328,6 +363,10 @@
     <Border Grid.RowSpan="4"
             ZIndex="30"
             Background="#C010151D"
+            Focusable="True"
+            KeyboardNavigation.TabNavigation="Cycle"
+            KeyDown="OnModalKeyDown"
+            AutomationProperties.Name="Update prompt modal dialog"
             IsVisible="{Binding UpdatePromptShell.IsOpen}">
       <Border Classes="card" Width="560" HorizontalAlignment="Center" VerticalAlignment="Center">
         <StackPanel Spacing="12">
@@ -336,8 +375,12 @@
           <Border Background="#24344B" Padding="10" CornerRadius="5">
             <TextBlock Text="{Binding UpdatePromptShell.Status}" TextWrapping="Wrap" />
           </Border>
-          <Button Content="Close"
+          <Button x:Name="UpdateCloseButton"
+                  Content="Close"
                   HorizontalAlignment="Right"
+                  IsCancel="True"
+                  IsDefault="True"
+                  AutomationProperties.Name="Close update prompt"
                   Command="{Binding UpdatePromptShell.CloseCommand}" />
         </StackPanel>
       </Border>

src/AcDream.Launcher/MainWindow.axaml.cs

@@ -1,5 +1,7 @@
+using System.ComponentModel;
 using AcDream.Launcher.ViewModels;
 using Avalonia.Controls;
+using Avalonia.Input;
 using Avalonia.Markup.Xaml;
 using Avalonia.Threading;
 
@@ -8,6 +10,9 @@ namespace AcDream.Launcher;
 public sealed partial class MainWindow : Window
 {
     private readonly DispatcherTimer _statusTimer;
+    private LauncherWindowViewModel? _observedViewModel;
+    private Control? _focusBeforeModal;
+    private bool _wasModalOpen;
 
     public MainWindow()
     {
@@ -17,6 +22,7 @@ public sealed partial class MainWindow : Window
             Interval = TimeSpan.FromMilliseconds(250),
         };
         _statusTimer.Tick += OnStatusTimerTick;
+        DataContextChanged += OnDataContextChanged;
         Opened += OnOpened;
         Closed += OnClosed;
     }
@@ -27,6 +33,8 @@ public sealed partial class MainWindow : Window
     {
         _statusTimer.Stop();
         _statusTimer.Tick -= OnStatusTimerTick;
+        DataContextChanged -= OnDataContextChanged;
+        ObserveViewModel(null);
         Opened -= OnOpened;
         Closed -= OnClosed;
     }
@@ -38,4 +46,92 @@ public sealed partial class MainWindow : Window
             viewModel.PollStatus();
         }
     }
+
+    private void OnDataContextChanged(object? sender, EventArgs e) =>
+        ObserveViewModel(DataContext as LauncherWindowViewModel);
+
+    private void ObserveViewModel(LauncherWindowViewModel? viewModel)
+    {
+        if (ReferenceEquals(_observedViewModel, viewModel))
+        {
+            return;
+        }
+
+        if (_observedViewModel is not null)
+        {
+            _observedViewModel.PropertyChanged -= OnViewModelPropertyChanged;
+        }
+
+        _observedViewModel = viewModel;
+        if (_observedViewModel is not null)
+        {
+            _observedViewModel.PropertyChanged += OnViewModelPropertyChanged;
+        }
+
+        _wasModalOpen = viewModel?.IsModalOpen == true;
+    }
+
+    private void OnViewModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName != nameof(LauncherWindowViewModel.IsModalOpen)
+            || sender is not LauncherWindowViewModel viewModel)
+        {
+            return;
+        }
+
+        bool isModalOpen = viewModel.IsModalOpen;
+        if (isModalOpen && !_wasModalOpen)
+        {
+            _focusBeforeModal = TopLevel.GetTopLevel(this)?.FocusManager?.GetFocusedElement() as Control;
+            Dispatcher.UIThread.Post(() => FocusActiveModal(viewModel));
+        }
+        else if (!isModalOpen && _wasModalOpen)
+        {
+            Control? focusToRestore = _focusBeforeModal;
+            _focusBeforeModal = null;
+            Dispatcher.UIThread.Post(() =>
+            {
+                if (focusToRestore?.Focus() != true)
+                {
+                    ProfilesTree.Focus();
+                }
+            });
+        }
+
+        _wasModalOpen = isModalOpen;
+    }
+
+    private void FocusActiveModal(LauncherWindowViewModel viewModel)
+    {
+        if (viewModel.EditorDialog.IsOpen)
+        {
+            Control target = viewModel.EditorDialog.Kind switch
+            {
+                ProfileEditorKind.AddServer or ProfileEditorKind.EditServer => ServerNameTextBox,
+                ProfileEditorKind.AddAccount or ProfileEditorKind.EditAccount => AccountNameTextBox,
+                ProfileEditorKind.AddCharacter or ProfileEditorKind.EditCharacter => CharacterNameTextBox,
+                _ => EditorSubmitButton,
+            };
+            target.Focus();
+        }
+        else if (viewModel.FirstRunWizardShell.IsOpen)
+        {
+            FirstRunCloseButton.Focus();
+        }
+        else if (viewModel.UpdatePromptShell.IsOpen)
+        {
+            UpdateCloseButton.Focus();
+        }
+    }
+
+    private void OnModalKeyDown(object? sender, KeyEventArgs e)
+    {
+        if (e.Key != Key.Escape || DataContext is not LauncherWindowViewModel viewModel)
+        {
+            return;
+        }
+
+        viewModel.CloseActiveModal();
+        e.Handled = true;
+    }
 }

src/AcDream.Launcher/Program.cs

@@ -5,8 +5,18 @@ namespace AcDream.Launcher;
 internal static class Program
 {
     [STAThread]
-    public static void Main(string[] args) =>
-        BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+    public static int Main(string[] args)
+    {
+        if (args is ["--verify-publish"])
+        {
+            // A display-free execution probe for the packaged artifact. CI
+            // runs this with DOTNET_ROOT pointing at a missing directory; a
+            // framework-dependent publish cannot reach this return statement.
+            return 0;
+        }
+
+        return BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+    }
 
     public static AppBuilder BuildAvaloniaApp() =>
         AppBuilder.Configure<App>()

src/AcDream.Launcher/ViewModels/Commands.cs

@@ -27,7 +27,13 @@ public sealed class RelayCommand : ICommand
 
     public bool CanExecute(object? parameter) => _canExecute?.Invoke(parameter) ?? true;
 
-    public void Execute(object? parameter) => _execute(parameter);
+    public void Execute(object? parameter)
+    {
+        if (CanExecute(parameter))
+        {
+            _execute(parameter);
+        }
+    }
 
     public void NotifyCanExecuteChanged() =>
         CanExecuteChanged?.Invoke(this, EventArgs.Empty);

src/AcDream.Launcher/ViewModels/LauncherSessionRowViewModel.cs

@@ -6,7 +6,8 @@ public sealed class LauncherSessionRowViewModel
 {
     public LauncherSessionRowViewModel(
         LauncherSessionSnapshot snapshot,
-        Func<string, Task> stop)
+        Func<string, Task> stop,
+        Func<bool>? canStop = null)
     {
         ArgumentNullException.ThrowIfNull(snapshot);
         ArgumentNullException.ThrowIfNull(stop);
@@ -24,7 +25,7 @@ public sealed class LauncherSessionRowViewModel
         IsActive = snapshot.IsActive;
         StopCommand = new AsyncRelayCommand(
             () => stop(SessionId),
-            () => IsActive);
+            () => IsActive && (canStop?.Invoke() ?? true));
     }
 
     public string SessionId { get; }
@@ -44,4 +45,6 @@ public sealed class LauncherSessionRowViewModel
     public bool IsActive { get; }
 
     public AsyncRelayCommand StopCommand { get; }
+
+    public void NotifyCommandState() => StopCommand.NotifyCanExecuteChanged();
 }

src/AcDream.Launcher/ViewModels/LauncherShellViewModel.cs

@@ -4,12 +4,16 @@ public sealed class LauncherShellViewModel : ObservableObject
 {
     private bool _isOpen;
 
-    public LauncherShellViewModel(string title, string body, string status)
+    public LauncherShellViewModel(
+        string title,
+        string body,
+        string status,
+        Func<bool>? canOpen = null)
     {
         Title = title;
         Body = body;
         Status = status;
-        OpenCommand = new RelayCommand(() => IsOpen = true);
+        OpenCommand = new RelayCommand(() => IsOpen = true, canOpen);
         CloseCommand = new RelayCommand(() => IsOpen = false);
     }
 
@@ -28,4 +32,10 @@ public sealed class LauncherShellViewModel : ObservableObject
     public RelayCommand OpenCommand { get; }
 
     public RelayCommand CloseCommand { get; }
+
+    public void NotifyCommandStates()
+    {
+        OpenCommand.NotifyCanExecuteChanged();
+        CloseCommand.NotifyCanExecuteChanged();
+    }
 }

src/AcDream.Launcher/ViewModels/LauncherWindowViewModel.cs

@@ -1,4 +1,5 @@
 using System.Collections.ObjectModel;
+using System.ComponentModel;
 using AcDream.Launcher.Core.Orchestration;
 using AcDream.Launcher.Core.Profiles;
 
@@ -33,22 +34,28 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
             "Choose and validate the retail DAT directory, build acdream.pak, "
                 + "and record the installed client. The installer transaction and "
                 + "progress body land in Campaign LA slice LA9.",
-            "Installer shell ready — implementation arrives in LA9.");
+            "Installer shell ready — implementation arrives in LA9.",
+            () => CanInteract);
         UpdatePromptShell = new LauncherShellViewModel(
             "Client update",
             "Review a signed release manifest, verify the downloaded archive, "
                 + "and atomically switch the installed client version. The updater "
                 + "transaction lands in Campaign LA slice LA10.",
-            "Updater shell ready — implementation arrives in LA10.");
+            "Updater shell ready — implementation arrives in LA10.",
+            () => CanInteract);
 
-        AddServerCommand = new RelayCommand(OpenAddServerDialog, () => !IsBusy);
+        EditorDialog.PropertyChanged += OnModalPropertyChanged;
+        FirstRunWizardShell.PropertyChanged += OnModalPropertyChanged;
+        UpdatePromptShell.PropertyChanged += OnModalPropertyChanged;
+
+        AddServerCommand = new RelayCommand(OpenAddServerDialog, () => CanInteract);
         AddAccountCommand = new RelayCommand(OpenAddAccountDialog, CanAddAccount);
         AddCharacterCommand = new RelayCommand(OpenAddCharacterDialog, CanAddCharacter);
         EditSelectedCommand = new RelayCommand(OpenEditSelectedDialog, CanEditSelected);
         RemoveSelectedCommand = new RelayCommand(OpenRemoveSelectedDialog, CanEditSelected);
         SaveCharacterSettingsCommand = new RelayCommand(
             SaveCharacterSettings,
-            () => IsCharacterSelected && !IsBusy);
+            () => IsCharacterSelected && CanInteract);
         RefreshCharactersCommand = new AsyncRelayCommand(
             RefreshCharactersAsync,
             () => CanProbe);
@@ -58,15 +65,18 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
         LaunchGuiSelectCommand = new AsyncRelayCommand(
             () => LaunchSelectedAsync(LaunchMode.GuiSelect),
             () => CanLaunchGuiSelect);
+        LaunchAccountGuiSelectCommand = new AsyncRelayCommand(
+            LaunchSelectedAccountGuiSelectAsync,
+            () => CanLaunchAccountGuiSelect);
         LaunchHeadlessCommand = new AsyncRelayCommand(
             () => LaunchSelectedAsync(LaunchMode.Headless),
             () => CanLaunchHeadless);
         CancelOperationCommand = new RelayCommand(
             CancelOperation,
-            () => IsBusy && _operationCancellation is not null);
+            () => !IsModalOpen && IsBusy && _operationCancellation is not null);
         ClearFinishedSessionsCommand = new RelayCommand(
             _orchestrator.ClearFinishedSessions,
-            () => Sessions.Any(session => !session.IsActive) && !IsBusy);
+            () => Sessions.Any(session => !session.IsActive) && CanInteract);
     }
 
     public ObservableCollection<LauncherTreeNodeViewModel> Servers { get; } = [];
@@ -99,6 +109,9 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
                 OnPropertyChanged(nameof(CanLaunchGui));
                 OnPropertyChanged(nameof(CanLaunchGuiSelect));
                 OnPropertyChanged(nameof(CanLaunchHeadless));
+                OnPropertyChanged(nameof(CanLaunchAccountGuiSelect));
+                OnPropertyChanged(nameof(ShowGuiLaunchDisabledReason));
+                OnPropertyChanged(nameof(ShowHeadlessLaunchDisabledReason));
                 NotifyCommandStates();
             }
         }
@@ -118,6 +131,13 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
 
     public bool HasError => !string.IsNullOrWhiteSpace(LastError);
 
+    public bool IsModalOpen =>
+        EditorDialog.IsOpen
+        || FirstRunWizardShell.IsOpen
+        || UpdatePromptShell.IsOpen;
+
+    private bool CanInteract => !IsBusy && !IsModalOpen;
+
     public string OperationStatus
     {
         get => _operationStatus;
@@ -172,7 +192,7 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
         _snapshot?.Platform.GraphicalLaunchDisabledReason ?? string.Empty;
 
     public bool CanProbe =>
-        !IsBusy
+        CanInteract
         && TryGetSelectedAccount(out string server, out string account)
         && _orchestrator.GetProbeCapability(server, account).IsAvailable;
 
@@ -196,14 +216,49 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
 
     public bool CanLaunchHeadless => CanLaunch(LaunchMode.Headless);
 
+    public bool CanLaunchAccountGuiSelect =>
+        CanInteract
+        && IsAccountSelected
+        && TryGetSelectedAccount(out string server, out string account)
+        && _orchestrator.GetAccountLaunchCapability(
+            server,
+            account,
+            LaunchMode.GuiSelect).IsAvailable;
+
+    public string AccountGuiSelectDisabledReason
+    {
+        get
+        {
+            if (!TryGetSelectedAccount(out string server, out string account))
+            {
+                return "Select an account.";
+            }
+
+            return _orchestrator.GetAccountLaunchCapability(
+                    server,
+                    account,
+                    LaunchMode.GuiSelect).Reason
+                ?? "Character-select launch is available.";
+        }
+    }
+
     public string GuiLaunchDisabledReason =>
-        _orchestrator.GetLaunchCapability(LaunchMode.Gui).Reason
+        GetSelectedAccountLaunchCapability(LaunchMode.Gui).Reason
         ?? "Graphical launch is available.";
 
     public string HeadlessLaunchDisabledReason =>
-        _orchestrator.GetLaunchCapability(LaunchMode.Headless).Reason
+        GetSelectedAccountLaunchCapability(LaunchMode.Headless).Reason
         ?? "Headless launch is available.";
 
+    public bool ShowGuiLaunchDisabledReason =>
+        IsCharacterSelected
+        && (!GetSelectedAccountLaunchCapability(LaunchMode.Gui).IsAvailable
+            || !GetSelectedAccountLaunchCapability(LaunchMode.GuiSelect).IsAvailable);
+
+    public bool ShowHeadlessLaunchDisabledReason =>
+        IsCharacterSelected
+        && !GetSelectedAccountLaunchCapability(LaunchMode.Headless).IsAvailable;
+
     public RelayCommand AddServerCommand { get; }
 
     public RelayCommand AddAccountCommand { get; }
@@ -222,6 +277,8 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
 
     public AsyncRelayCommand LaunchGuiSelectCommand { get; }
 
+    public AsyncRelayCommand LaunchAccountGuiSelectCommand { get; }
+
     public AsyncRelayCommand LaunchHeadlessCommand { get; }
 
     public RelayCommand CancelOperationCommand { get; }
@@ -272,6 +329,9 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
         _operationCancellation?.Dispose();
         _operationCancellation = null;
         _orchestrator.StateChanged -= OnOrchestratorStateChanged;
+        EditorDialog.PropertyChanged -= OnModalPropertyChanged;
+        FirstRunWizardShell.PropertyChanged -= OnModalPropertyChanged;
+        UpdatePromptShell.PropertyChanged -= OnModalPropertyChanged;
     }
 
     private void OnOrchestratorStateChanged(object? sender, EventArgs e) =>
@@ -283,6 +343,41 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
             }
         });
 
+    private void OnModalPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName != nameof(ProfileEditorDialogViewModel.IsOpen)
+            && e.PropertyName != nameof(LauncherShellViewModel.IsOpen))
+        {
+            return;
+        }
+
+        OnPropertyChanged(nameof(IsModalOpen));
+        OnPropertyChanged(nameof(CanProbe));
+        OnPropertyChanged(nameof(CanLaunchGui));
+        OnPropertyChanged(nameof(CanLaunchGuiSelect));
+        OnPropertyChanged(nameof(CanLaunchHeadless));
+        OnPropertyChanged(nameof(CanLaunchAccountGuiSelect));
+        OnPropertyChanged(nameof(ShowGuiLaunchDisabledReason));
+        OnPropertyChanged(nameof(ShowHeadlessLaunchDisabledReason));
+        NotifyCommandStates();
+    }
+
+    public void CloseActiveModal()
+    {
+        if (EditorDialog.IsOpen)
+        {
+            EditorDialog.Close();
+        }
+        else if (FirstRunWizardShell.IsOpen)
+        {
+            FirstRunWizardShell.IsOpen = false;
+        }
+        else if (UpdatePromptShell.IsOpen)
+        {
+            UpdatePromptShell.IsOpen = false;
+        }
+    }
+
     private void RefreshFromCore(SelectionKey? preferredSelection = null)
     {
         SelectionKey? previousSelection = preferredSelection ?? SelectionKey.From(SelectedNode);
@@ -298,7 +393,10 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
         Sessions.Clear();
         foreach (LauncherSessionSnapshot session in snapshot.Sessions)
         {
-            Sessions.Add(new LauncherSessionRowViewModel(session, StopSessionAsync));
+            Sessions.Add(new LauncherSessionRowViewModel(
+                session,
+                StopSessionAsync,
+                () => CanInteract));
         }
 
         LauncherTreeNodeViewModel? restored = previousSelection is null
@@ -317,8 +415,12 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
         OnPropertyChanged(nameof(CanLaunchGui));
         OnPropertyChanged(nameof(CanLaunchGuiSelect));
         OnPropertyChanged(nameof(CanLaunchHeadless));
+        OnPropertyChanged(nameof(CanLaunchAccountGuiSelect));
+        OnPropertyChanged(nameof(AccountGuiSelectDisabledReason));
         OnPropertyChanged(nameof(GuiLaunchDisabledReason));
         OnPropertyChanged(nameof(HeadlessLaunchDisabledReason));
+        OnPropertyChanged(nameof(ShowGuiLaunchDisabledReason));
+        OnPropertyChanged(nameof(ShowHeadlessLaunchDisabledReason));
         NotifyCommandStates();
     }
 
@@ -353,6 +455,12 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
         OnPropertyChanged(nameof(CanLaunchGui));
         OnPropertyChanged(nameof(CanLaunchGuiSelect));
         OnPropertyChanged(nameof(CanLaunchHeadless));
+        OnPropertyChanged(nameof(CanLaunchAccountGuiSelect));
+        OnPropertyChanged(nameof(AccountGuiSelectDisabledReason));
+        OnPropertyChanged(nameof(GuiLaunchDisabledReason));
+        OnPropertyChanged(nameof(HeadlessLaunchDisabledReason));
+        OnPropertyChanged(nameof(ShowGuiLaunchDisabledReason));
+        OnPropertyChanged(nameof(ShowHeadlessLaunchDisabledReason));
         NotifyCommandStates();
     }
 
@@ -387,7 +495,7 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
                     null));
             });
 
-    private bool CanAddAccount() => !IsBusy && SelectedNode is not null;
+    private bool CanAddAccount() => CanInteract && SelectedNode is not null;
 
     private void OpenAddAccountDialog()
     {
@@ -411,7 +519,7 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
     }
 
     private bool CanAddCharacter() =>
-        !IsBusy && TryGetSelectedAccount(out _, out _);
+        CanInteract && TryGetSelectedAccount(out _, out _);
 
     private void OpenAddCharacterDialog()
     {
@@ -441,7 +549,7 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
                 + "let you configure a known character while the server is unavailable.");
     }
 
-    private bool CanEditSelected() => !IsBusy && SelectedNode is not null;
+    private bool CanEditSelected() => CanInteract && SelectedNode is not null;
 
     private void OpenEditSelectedDialog()
     {
@@ -642,6 +750,24 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
             $"{mode} session started for {character.Name}.");
     }
 
+    private Task LaunchSelectedAccountGuiSelectAsync()
+    {
+        if (!TryGetSelectedAccount(out string serverName, out string accountName))
+        {
+            return Task.CompletedTask;
+        }
+
+        return RunOperationAsync(
+            token => _orchestrator.LaunchAsync(
+                serverName,
+                accountName,
+                null,
+                LaunchMode.GuiSelect,
+                token),
+            $"Opening character select for {accountName}…",
+            $"Character-select session started for {accountName}.");
+    }
+
     private async Task RunOperationAsync(
         Func<CancellationToken, Task<LauncherSessionSnapshot>> operation,
         string activeStatus,
@@ -728,9 +854,15 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
     private void CancelOperation() => _operationCancellation?.Cancel();
 
     private bool CanLaunch(LaunchMode mode) =>
-        !IsBusy
+        CanInteract
         && IsCharacterSelected
-        && _orchestrator.GetLaunchCapability(mode).IsAvailable;
+        && TryGetSelectedAccount(out string server, out string account)
+        && _orchestrator.GetAccountLaunchCapability(server, account, mode).IsAvailable;
+
+    private LauncherCapability GetSelectedAccountLaunchCapability(LaunchMode mode) =>
+        TryGetSelectedAccount(out string server, out string account)
+            ? _orchestrator.GetAccountLaunchCapability(server, account, mode)
+            : _orchestrator.GetLaunchCapability(mode);
 
     private bool TryGetSelectedAccount(out string serverName, out string accountName)
     {
@@ -843,9 +975,16 @@ public sealed class LauncherWindowViewModel : ObservableObject, IDisposable
         RefreshCharactersCommand.NotifyCanExecuteChanged();
         LaunchGuiCommand.NotifyCanExecuteChanged();
         LaunchGuiSelectCommand.NotifyCanExecuteChanged();
+        LaunchAccountGuiSelectCommand.NotifyCanExecuteChanged();
         LaunchHeadlessCommand.NotifyCanExecuteChanged();
         CancelOperationCommand.NotifyCanExecuteChanged();
         ClearFinishedSessionsCommand.NotifyCanExecuteChanged();
+        foreach (LauncherSessionRowViewModel session in Sessions)
+        {
+            session.NotifyCommandState();
+        }
+        FirstRunWizardShell.NotifyCommandStates();
+        UpdatePromptShell.NotifyCommandStates();
     }
 
     private readonly record struct SelectionKey(

tests/AcDream.Launcher.Core.Tests/Orchestration/LauncherExecutableSetTests.cs

@@ -0,0 +1,67 @@
+using AcDream.Launcher.Core.Orchestration;
+using AcDream.Launcher.Core.Profiles;
+
+namespace AcDream.Launcher.Core.Tests.Orchestration;
+
+public sealed class LauncherExecutableSetTests : IDisposable
+{
+    private readonly string _root = Path.Combine(
+        Path.GetTempPath(),
+        "acdream-launcher-layout-tests",
+        Guid.NewGuid().ToString("N"));
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_root))
+        {
+            Directory.Delete(_root, recursive: true);
+        }
+    }
+
+    [Fact]
+    public void FromDirectoryResolvesThePublishedCoDeploymentLayout()
+    {
+        Directory.CreateDirectory(_root);
+        string suffix = OperatingSystem.IsWindows() ? ".exe" : string.Empty;
+        string graphical = Path.Combine(_root, "AcDream.App" + suffix);
+        string headless = Path.Combine(_root, "acdream-headless" + suffix);
+        File.WriteAllText(graphical, string.Empty);
+        File.WriteAllText(headless, string.Empty);
+
+        LauncherExecutableSet set = LauncherExecutableSet.FromDirectory(_root);
+
+        Assert.Equal(Path.GetFullPath(_root), set.WorkingDirectory);
+        Assert.Equal(graphical, set.GraphicalHostPath);
+        Assert.Equal(headless, set.HeadlessHostPath);
+        Assert.True(set.GetAvailability(LaunchMode.Gui).IsAvailable);
+        Assert.True(set.GetAvailability(LaunchMode.GuiSelect).IsAvailable);
+        Assert.True(set.GetAvailability(LaunchMode.Headless).IsAvailable);
+        Assert.Equal(
+            graphical,
+            set.CreatePlaySpec(LaunchMode.GuiSelect, "session.json").ExecutablePath);
+        Assert.Equal(
+            headless,
+            set.CreateProbeSpec("session.json").ExecutablePath);
+    }
+
+    [Fact]
+    public void MissingPublishedHostsHaveSpecificUnavailableReasons()
+    {
+        Directory.CreateDirectory(_root);
+        LauncherExecutableSet set = LauncherExecutableSet.FromDirectory(_root);
+
+        LauncherCapability gui = set.GetAvailability(LaunchMode.Gui);
+        LauncherCapability probe = set.GetAvailability(LaunchMode.Headless);
+
+        Assert.False(gui.IsAvailable);
+        Assert.Contains("graphical client", gui.Reason, StringComparison.Ordinal);
+        Assert.Contains(set.GraphicalHostPath, gui.Reason, StringComparison.Ordinal);
+        Assert.False(probe.IsAvailable);
+        Assert.Contains("headless host", probe.Reason, StringComparison.Ordinal);
+        Assert.Contains(set.HeadlessHostPath, probe.Reason, StringComparison.Ordinal);
+        Assert.Throws<LauncherOperationException>(() =>
+            set.CreatePlaySpec(LaunchMode.Gui, "session.json"));
+        Assert.Throws<LauncherOperationException>(() =>
+            set.CreateProbeSpec("session.json"));
+    }
+}

tests/AcDream.Launcher.Core.Tests/Orchestration/LauncherOrchestratorTests.cs

@@ -106,6 +106,59 @@ public sealed class LauncherOrchestratorTests : IDisposable
         Assert.Contains("+Acdream", inWorld.Status, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public async Task AccountGuiSelectDoesNotRequireACachedCharacterOrEmitASelector()
+    {
+        var config = new RecordingConfigService();
+        var supervisors = new FakeSupervisorFactory();
+        using LauncherOrchestrator orchestrator = CreateOrchestrator(
+            includeCharacter: false,
+            configService: config,
+            supervisorFactory: supervisors);
+
+        Assert.True(orchestrator.GetAccountLaunchCapability(
+            "Local ACE",
+            "testaccount",
+            LaunchMode.GuiSelect).IsAvailable);
+
+        LauncherSessionSnapshot launched = await orchestrator.LaunchAsync(
+            "Local ACE",
+            "testaccount",
+            characterName: null,
+            LaunchMode.GuiSelect);
+
+        Assert.Null(launched.CharacterName);
+        Assert.Equal(LaunchMode.GuiSelect, config.LastCharacter!.LaunchMode);
+        Assert.Equal(string.Empty, config.LastCharacter.Name);
+        string json = SessionConfigComposer.Serialize(config.LastComposed!.Document);
+        Assert.DoesNotContain("\"character\"", json, StringComparison.Ordinal);
+        Assert.DoesNotContain(Password, json, StringComparison.Ordinal);
+        Assert.Equal("gui-host", Assert.Single(supervisors.Created).Spec!.ExecutablePath);
+    }
+
+    [Theory]
+    [InlineData(LaunchMode.Gui)]
+    [InlineData(LaunchMode.Headless)]
+    public async Task AccountLaunchWithoutACharacterOnlyAcceptsGuiSelect(LaunchMode mode)
+    {
+        var config = new RecordingConfigService();
+        var supervisors = new FakeSupervisorFactory();
+        using LauncherOrchestrator orchestrator = CreateOrchestrator(
+            includeCharacter: false,
+            configService: config,
+            supervisorFactory: supervisors);
+
+        await Assert.ThrowsAsync<LauncherOperationException>(() =>
+            orchestrator.LaunchAsync(
+                "Local ACE",
+                "testaccount",
+                characterName: null,
+                mode));
+
+        Assert.Equal(0, config.PlayCallCount);
+        Assert.Empty(supervisors.Created);
+    }
+
     [Fact]
     public async Task ProbeIsRefusedWhileTheAccountHasARunningLauncherActivity()
     {
@@ -126,6 +179,58 @@ public sealed class LauncherOrchestratorTests : IDisposable
             orchestrator.ProbeAsync("Local ACE", "testaccount"));
     }
 
+    [Fact]
+    public async Task LaunchIsRefusedWhileTheAccountProbeIsRunning()
+    {
+        using LauncherOrchestrator orchestrator = CreateOrchestrator();
+        await orchestrator.ProbeAsync("Local ACE", "testaccount");
+
+        LauncherCapability capability = orchestrator.GetAccountLaunchCapability(
+            "Local ACE",
+            "testaccount",
+            LaunchMode.Headless);
+
+        Assert.False(capability.IsAvailable);
+        await Assert.ThrowsAsync<LauncherOperationException>(() =>
+            orchestrator.LaunchAsync(
+                "Local ACE",
+                "testaccount",
+                "+Acdream",
+                LaunchMode.Headless));
+    }
+
+    [Fact]
+    public async Task ConcurrentPlayReservationsAllowExactlyOneActivityPerAccount()
+    {
+        using LauncherOrchestrator orchestrator = CreateOrchestrator();
+
+        Task<LauncherSessionSnapshot>[] attempts = Enumerable.Range(0, 2)
+            .Select(_ => Task.Run(async () => await orchestrator.LaunchAsync(
+                "Local ACE",
+                "testaccount",
+                "+Acdream",
+                LaunchMode.Headless)))
+            .ToArray();
+
+        try
+        {
+            await Task.WhenAll(attempts);
+        }
+        catch (LauncherOperationException)
+        {
+            // The losing reservation is the behavior under test.
+        }
+
+        Task<LauncherSessionSnapshot> successful = Assert.Single(
+            attempts,
+            attempt => attempt.Status == TaskStatus.RanToCompletion);
+        Task<LauncherSessionSnapshot> rejected = Assert.Single(attempts, attempt =>
+            attempt.Exception?.GetBaseException() is LauncherOperationException);
+        Assert.True(successful.IsCompletedSuccessfully);
+        Assert.True(rejected.IsFaulted);
+        Assert.Single(orchestrator.GetSnapshot().Sessions);
+    }
+
     [Fact]
     public async Task ProbeUsesTheProbeShapeAndFoldsTheReportedRosterIntoTheStore()
     {
@@ -206,6 +311,103 @@ public sealed class LauncherOrchestratorTests : IDisposable
         Assert.Empty(supervisors.Created);
     }
 
+    [Fact]
+    public async Task MissingCoDeployedHostsDisableActionsBeforeCompositionOrSpawn()
+    {
+        var config = new RecordingConfigService();
+        var supervisors = new FakeSupervisorFactory();
+        var executables = new LauncherExecutableSet(
+            "missing-gui",
+            "missing-headless",
+            fileExists: _ => false);
+        using LauncherOrchestrator orchestrator = CreateOrchestrator(
+            configService: config,
+            supervisorFactory: supervisors,
+            executables: executables);
+
+        LauncherCapability gui = orchestrator.GetAccountLaunchCapability(
+            "Local ACE",
+            "testaccount",
+            LaunchMode.GuiSelect);
+        LauncherCapability headless = orchestrator.GetAccountLaunchCapability(
+            "Local ACE",
+            "testaccount",
+            LaunchMode.Headless);
+        LauncherCapability probe = orchestrator.GetProbeCapability(
+            "Local ACE",
+            "testaccount");
+
+        Assert.False(gui.IsAvailable);
+        Assert.Contains("missing-gui", gui.Reason, StringComparison.Ordinal);
+        Assert.False(headless.IsAvailable);
+        Assert.Contains("missing-headless", headless.Reason, StringComparison.Ordinal);
+        Assert.False(probe.IsAvailable);
+        await Assert.ThrowsAsync<LauncherOperationException>(() =>
+            orchestrator.LaunchAsync(
+                "Local ACE",
+                "testaccount",
+                "+Acdream",
+                LaunchMode.Headless));
+        Assert.Equal(0, config.PlayCallCount);
+        Assert.Empty(supervisors.Created);
+    }
+
+    [Fact]
+    public async Task ProcessExitIsTerminalAndLateStatusCannotResurrectTheAccount()
+    {
+        var supervisors = new FakeSupervisorFactory();
+        var statusSources = new QueueStatusSourceFactory();
+        using LauncherOrchestrator orchestrator = CreateOrchestrator(
+            supervisorFactory: supervisors,
+            statusSourceFactory: statusSources);
+        await orchestrator.LaunchAsync(
+            "Local ACE",
+            "testaccount",
+            "+Acdream",
+            LaunchMode.Headless);
+
+        Assert.Single(supervisors.Created).Exit(23);
+        QueueStatusSource source = Assert.Single(statusSources.Created);
+        source.Enqueue(Connected("s1"));
+        source.Enqueue(EnteredWorld("s1", "+Acdream"));
+        source.Enqueue(Exited("s1", 23, "host crash detail"));
+        orchestrator.PollStatus();
+
+        LauncherSessionSnapshot session = Assert.Single(orchestrator.GetSnapshot().Sessions);
+        Assert.Equal(LauncherActivityState.Exited, session.State);
+        Assert.Equal(23, session.ExitCode);
+        Assert.Contains("host crash detail", session.Status, StringComparison.Ordinal);
+        Assert.True(orchestrator.GetProbeCapability("Local ACE", "testaccount").IsAvailable);
+    }
+
+    [Fact]
+    public async Task HostExitReasonSurvivesTheLaterProcessExitCallback()
+    {
+        var supervisors = new FakeSupervisorFactory();
+        var statusSources = new QueueStatusSourceFactory();
+        using LauncherOrchestrator orchestrator = CreateOrchestrator(
+            supervisorFactory: supervisors,
+            statusSourceFactory: statusSources);
+        await orchestrator.LaunchAsync(
+            "Local ACE",
+            "testaccount",
+            "+Acdream",
+            LaunchMode.Headless);
+
+        Assert.Single(statusSources.Created).Enqueue(
+            Exited("s1", 0, "graceful host shutdown"));
+        orchestrator.PollStatus();
+        Assert.Single(supervisors.Created).Exit(0);
+
+        LauncherSessionSnapshot session = Assert.Single(orchestrator.GetSnapshot().Sessions);
+        Assert.Equal(LauncherActivityState.Exited, session.State);
+        Assert.Contains("graceful host shutdown", session.Status, StringComparison.Ordinal);
+        Assert.True(orchestrator.GetAccountLaunchCapability(
+            "Local ACE",
+            "testaccount",
+            LaunchMode.Headless).IsAvailable);
+    }
+
     [Fact]
     public async Task StartFailureIsVisibleButRedactsTheCredentialEverywhere()
     {
@@ -286,7 +488,8 @@ public sealed class LauncherOrchestratorTests : IDisposable
         LauncherPlatformCapabilities? platform = null,
         ILauncherSessionConfigService? configService = null,
         ILauncherProcessSupervisorFactory? supervisorFactory = null,
-        IStatusEventSourceFactory? statusSourceFactory = null)
+        IStatusEventSourceFactory? statusSourceFactory = null,
+        LauncherExecutableSet? executables = null)
     {
         string profilePath = Path.Combine(
             _paths.ConfigDirectory,
@@ -312,7 +515,10 @@ public sealed class LauncherOrchestratorTests : IDisposable
         var orchestrator = new LauncherOrchestrator(
             store,
             _paths,
-            new LauncherExecutableSet("gui-host", "headless-host"),
+            executables ?? new LauncherExecutableSet(
+                "gui-host",
+                "headless-host",
+                fileExists: _ => true),
             new LauncherInstallRecord("dats", "pak"),
             platform ?? WindowsCapabilities(),
             configService,
@@ -357,6 +563,20 @@ public sealed class LauncherOrchestratorTests : IDisposable
             CharacterName = characterName,
         };
 
+    private static ExitedStatusEvent Exited(
+        string sessionId,
+        int code,
+        string reason) =>
+        new()
+        {
+            V = 1,
+            E = "exited",
+            T = DateTimeOffset.UtcNow,
+            SessionId = sessionId,
+            Code = code,
+            Reason = reason,
+        };
+
     private sealed class RecordingConfigService : ILauncherSessionConfigService
     {
         public int PlayCallCount { get; private set; }
@@ -462,6 +682,13 @@ public sealed class LauncherOrchestratorTests : IDisposable
             StateChanged?.Invoke(this, State);
         }
 
+        public void Exit(int code)
+        {
+            State = LauncherSessionState.Exited;
+            ExitCode = code;
+            StateChanged?.Invoke(this, State);
+        }
+
         public void Dispose()
         {
         }

tests/AcDream.Launcher.Core.Tests/Profiles/LauncherProfileHardeningTests.cs

@@ -0,0 +1,171 @@
+using System.Text.Json;
+using AcDream.Launcher.Core.Profiles;
+
+namespace AcDream.Launcher.Core.Tests.Profiles;
+
+public sealed class LauncherProfileHardeningTests : IDisposable
+{
+    private readonly string _root = Path.Combine(
+        Path.GetTempPath(),
+        "acdream-launcher-profile-hardening-tests",
+        Guid.NewGuid().ToString("N"));
+    private readonly string _filePath;
+
+    public LauncherProfileHardeningTests()
+    {
+        Directory.CreateDirectory(_root);
+        _filePath = Path.Combine(_root, "launcher-profiles.json");
+    }
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_root))
+        {
+            Directory.Delete(_root, recursive: true);
+        }
+    }
+
+    [Fact]
+    public void MultiFieldEditValidatesEverythingBeforeChangingAnything()
+    {
+        LauncherProfileStore store = CreatePopulatedStore();
+
+        Assert.Throws<LauncherProfileException>(() =>
+            store.EditServer(
+                "Local ACE",
+                newName: "Partially renamed",
+                newHost: "changed.example.test",
+                newPort: 0));
+        ServerProfile server = Assert.Single(store.Document.Servers);
+        Assert.Equal("Local ACE", server.Name);
+        Assert.Equal("127.0.0.1", server.Host);
+        Assert.Equal(9000, server.Port);
+
+        Assert.Throws<LauncherProfileException>(() =>
+            store.EditCharacter(
+                "Local ACE",
+                "testaccount",
+                "+Acdream",
+                newName: "+PartiallyRenamed",
+                newId: "not-an-id"));
+        CharacterProfile character = Assert.Single(server.Accounts.Single().Characters);
+        Assert.Equal("+Acdream", character.Name);
+        Assert.Equal("0x5000000A", character.Id);
+    }
+
+    [Fact]
+    public void TransactionRestoresTheExactDocumentWhenPersistenceFails()
+    {
+        Directory.CreateDirectory(_filePath);
+        var store = new LauncherProfileStore(_filePath);
+        store.Load();
+
+        Assert.ThrowsAny<Exception>(() =>
+            store.ExecuteTransaction(() =>
+                store.AddServer("Should roll back", "host", 9000)));
+
+        Assert.Empty(store.Document.Servers);
+        Assert.False(File.Exists(_filePath + ".tmp"));
+    }
+
+    [Fact]
+    public void TransactionRestoresNestedCredentialAndSettingsOnMutationFailure()
+    {
+        LauncherProfileStore store = CreatePopulatedStore();
+        string before = JsonSerializer.Serialize(store.Document);
+
+        Assert.Throws<InvalidOperationException>(() =>
+            store.ExecuteTransaction(() =>
+            {
+                AccountProfile account = store.Document.Servers.Single().Accounts.Single();
+                account.Password = "transient-secret";
+                account.Characters.Single().Plugins.Add("Transient.Plugin");
+                throw new InvalidOperationException("simulated mutation failure");
+            }));
+
+        Assert.Equal(before, JsonSerializer.Serialize(store.Document));
+    }
+
+    public static TheoryData<string> InvalidDocuments => new()
+    {
+        { """{"version":1,"servers":null}""" },
+        { """{"version":1,"servers":[null]}""" },
+        { """{"version":1,"servers":[{"name":" ","host":"h","port":9000,"accounts":[]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":" ","port":9000,"accounts":[]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":0,"accounts":[]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[]},{"name":"s","host":"h2","port":9001,"accounts":[]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[]},{"account":"a","password":"p2","characters":[]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":null,"characters":[]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":null}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[{"name":"c","id":"0x00000000","launchMode":"gui","plugins":[],"loginCommands":[]}]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[{"name":"c","id":"0x50000001","launchMode":"invalid","plugins":[],"loginCommands":[]}]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[{"name":"c","id":"0x50000001","launchMode":"gui","plugins":null,"loginCommands":[]}]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[{"name":"c","id":"0x50000001","launchMode":"gui","plugins":["P","P"],"loginCommands":[]}]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[{"name":"c","id":"0x50000001","launchMode":"gui","plugins":[],"loginCommands":[" "]}]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[{"name":"c","id":"0x50000001","launchMode":"gui","plugins":[],"loginCommands":[]},{"name":"c","id":"0x50000002","launchMode":"gui","plugins":[],"loginCommands":[]}]}]}]}""" },
+        { """{"version":1,"servers":[{"name":"s","host":"h","port":9000,"accounts":[{"account":"a","password":"p","characters":[{"name":"c1","id":"0x50000001","launchMode":"gui","plugins":[],"loginCommands":[]},{"name":"c2","id":"0x50000001","launchMode":"gui","plugins":[],"loginCommands":[]}]}]}]}""" },
+    };
+
+    [Theory]
+    [MemberData(nameof(InvalidDocuments))]
+    public void LoadRejectsSemanticallyInvalidDocuments(string json)
+    {
+        File.WriteAllText(_filePath, json);
+        var store = new LauncherProfileStore(_filePath);
+
+        Assert.Throws<LauncherProfileException>(() => store.Load());
+    }
+
+    [Fact]
+    public void FailedLoadDoesNotReplaceAnAlreadyLoadedDocument()
+    {
+        LauncherProfileStore store = CreatePopulatedStore();
+        File.WriteAllText(_filePath, """{"version":1,"servers":null}""");
+
+        Assert.Throws<LauncherProfileException>(() => store.Load());
+
+        Assert.Equal("Local ACE", Assert.Single(store.Document.Servers).Name);
+    }
+
+    [Fact]
+    public void LinuxLoadNormalizesAnExistingCredentialFileTo0600BeforeReading()
+    {
+        if (!OperatingSystem.IsLinux())
+        {
+            return;
+        }
+
+        File.WriteAllText(_filePath, """{"version":1,"servers":[]}""");
+        File.SetUnixFileMode(
+            _filePath,
+            UnixFileMode.UserRead
+            | UnixFileMode.UserWrite
+            | UnixFileMode.GroupRead
+            | UnixFileMode.OtherRead);
+
+        var store = new LauncherProfileStore(_filePath);
+        Assert.True(store.Load());
+
+        Assert.Equal(
+            UnixFileMode.UserRead | UnixFileMode.UserWrite,
+            File.GetUnixFileMode(_filePath));
+    }
+
+    private LauncherProfileStore CreatePopulatedStore()
+    {
+        var store = new LauncherProfileStore(_filePath);
+        store.Load();
+        store.AddServer("Local ACE", "127.0.0.1", 9000);
+        store.AddAccount("Local ACE", "testaccount", "password");
+        store.AddCharacter(
+            "Local ACE",
+            "testaccount",
+            "+Acdream",
+            "0x5000000A",
+            LaunchMode.Headless,
+            ["ExamplePlugin"],
+            ["/vt start"]);
+        store.Save();
+        return store;
+    }
+}

tests/AcDream.Launcher.Core.Tests/Profiles/RosterMergeTests.cs

@@ -152,6 +152,66 @@ public sealed class RosterMergeTests
         Assert.Equal("+Acdream", character.Name);
     }
 
+    [Fact]
+    public void SameNameRosterEntryCorrectsAWrongValidIdAndPreservesSettings()
+    {
+        LauncherProfileStore store = NewStoreWithServerAndAccount();
+        store.AddCharacter(
+            "Local ACE",
+            "testaccount",
+            "+Acdream",
+            "0x50000001",
+            LaunchMode.Headless,
+            ["ExamplePlugin"],
+            ["/vt start"]);
+
+        store.MergeRoster(
+            "Local ACE",
+            "testaccount",
+            [new CharacterRosterEntry(0x5000000A, "+Acdream", 0)]);
+
+        CharacterProfile character = Assert.Single(
+            store.Document.Servers.Single().Accounts.Single().Characters);
+        Assert.Equal("0x5000000A", character.Id);
+        Assert.Equal(LaunchMode.Headless, character.LaunchMode);
+        Assert.Equal(["ExamplePlugin"], character.Plugins);
+        Assert.Equal(["/vt start"], character.LoginCommands);
+    }
+
+    [Fact]
+    public void AuthoritativeMergeCollapsesCorrectIdAndSameNameDuplicates()
+    {
+        LauncherProfileStore store = NewStoreWithServerAndAccount();
+        AccountProfile account = store.Document.Servers.Single().Accounts.Single();
+        account.Characters.Add(new CharacterProfile
+        {
+            Id = "0x5000000A",
+            Name = "+OldName",
+            LaunchMode = LaunchMode.Headless,
+            Plugins = ["Canonical.Plugin"],
+            LoginCommands = ["/canonical"],
+        });
+        account.Characters.Add(new CharacterProfile
+        {
+            Id = "0x50000001",
+            Name = "+Acdream",
+            LaunchMode = LaunchMode.Gui,
+            Plugins = ["Duplicate.Plugin"],
+            LoginCommands = ["/duplicate"],
+        });
+
+        store.MergeRoster(
+            "Local ACE",
+            "testaccount",
+            [new CharacterRosterEntry(0x5000000A, "+Acdream", 0)]);
+
+        CharacterProfile character = Assert.Single(account.Characters);
+        Assert.Equal("0x5000000A", character.Id);
+        Assert.Equal("+Acdream", character.Name);
+        Assert.Equal(LaunchMode.Headless, character.LaunchMode);
+        Assert.Equal(["Canonical.Plugin"], character.Plugins);
+    }
+
     [Fact]
     public void MergeThrowsForUnknownServerOrAccount()
     {

tests/AcDream.Launcher.Tests/LauncherProjectBoundaryTests.cs

@@ -1,3 +1,4 @@
+using System.Diagnostics;
 using System.Xml.Linq;
 
 namespace AcDream.Launcher.Tests;
@@ -56,6 +57,95 @@ public sealed class LauncherProjectBoundaryTests
         Assert.Contains("tests/AcDream.Launcher.Tests/AcDream.Launcher.Tests.csproj", paths);
     }
 
+    [Fact]
+    public void LinuxPublishEvaluatesAsSelfContainedSingleFile()
+    {
+        string root = FindRepositoryRoot();
+        string projectPath = Path.Combine(
+            root,
+            "src",
+            "AcDream.Launcher",
+            "AcDream.Launcher.csproj");
+
+        Assert.Equal("true", EvaluateProperty(projectPath, "SelfContained"));
+        Assert.Equal("true", EvaluateProperty(projectPath, "PublishSingleFile"));
+    }
+
+    [Fact]
+    public void ModalMarkupAndCodeBehindCarryKeyboardFocusAndAccessibilityGuards()
+    {
+        string root = FindRepositoryRoot();
+        string markup = File.ReadAllText(Path.Combine(
+            root,
+            "src",
+            "AcDream.Launcher",
+            "MainWindow.axaml"));
+        string codeBehind = File.ReadAllText(Path.Combine(
+            root,
+            "src",
+            "AcDream.Launcher",
+            "MainWindow.axaml.cs"));
+
+        Assert.Equal(3, Count(markup, "KeyboardNavigation.TabNavigation=\"Cycle\""));
+        Assert.Equal(3, Count(markup, "KeyDown=\"OnModalKeyDown\""));
+        Assert.True(Count(markup, "AutomationProperties.Name=") >= 13);
+        Assert.True(Count(markup, "IsDefault=\"True\"") >= 3);
+        Assert.True(Count(markup, "IsCancel=\"True\"") >= 3);
+        Assert.Contains("ServerNameTextBox", markup, StringComparison.Ordinal);
+        Assert.Contains("AccountNameTextBox", markup, StringComparison.Ordinal);
+        Assert.Contains("CharacterNameTextBox", markup, StringComparison.Ordinal);
+        Assert.Contains("FocusActiveModal", codeBehind, StringComparison.Ordinal);
+        Assert.Contains("_focusBeforeModal", codeBehind, StringComparison.Ordinal);
+        Assert.Contains("Key.Escape", codeBehind, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void PortabilityWorkflowBuildsTestsPublishesAndExecutesTheLauncher()
+    {
+        string workflow = File.ReadAllText(Path.Combine(
+            FindRepositoryRoot(),
+            ".github",
+            "workflows",
+            "headless-portability.yml"));
+
+        Assert.Contains("src/AcDream.Launcher/**", workflow, StringComparison.Ordinal);
+        Assert.Contains("tests/AcDream.Launcher.Tests/**", workflow, StringComparison.Ordinal);
+        Assert.Contains("portable-launcher:", workflow, StringComparison.Ordinal);
+        Assert.Contains("tests/AcDream.Launcher.Tests/AcDream.Launcher.Tests.csproj", workflow, StringComparison.Ordinal);
+        Assert.Contains("-r linux-x64", workflow, StringComparison.Ordinal);
+        Assert.Contains("-getProperty:SelfContained", workflow, StringComparison.Ordinal);
+        Assert.Contains("DOTNET_ROOT", workflow, StringComparison.Ordinal);
+        Assert.Contains("--verify-publish", workflow, StringComparison.Ordinal);
+    }
+
+    private static string EvaluateProperty(string projectPath, string property)
+    {
+        var startInfo = new ProcessStartInfo("dotnet")
+        {
+            RedirectStandardError = true,
+            RedirectStandardOutput = true,
+            UseShellExecute = false,
+        };
+        startInfo.ArgumentList.Add("msbuild");
+        startInfo.ArgumentList.Add(projectPath);
+        startInfo.ArgumentList.Add("-nologo");
+        startInfo.ArgumentList.Add("-property:RuntimeIdentifier=linux-x64");
+        startInfo.ArgumentList.Add($"-getProperty:{property}");
+
+        using Process process = Process.Start(startInfo)
+            ?? throw new InvalidOperationException("Could not start dotnet msbuild.");
+        string output = process.StandardOutput.ReadToEnd();
+        string error = process.StandardError.ReadToEnd();
+        Assert.True(process.WaitForExit(30_000), "dotnet msbuild did not exit.");
+        Assert.True(
+            process.ExitCode == 0,
+            $"dotnet msbuild exited {process.ExitCode}: {error}");
+        return output.Trim();
+    }
+
+    private static int Count(string text, string value) =>
+        text.Split(value, StringSplitOptions.None).Length - 1;
+
     private static string FindRepositoryRoot()
     {
         foreach (string start in new[] { AppContext.BaseDirectory, Environment.CurrentDirectory })

tests/AcDream.Launcher.Tests/LauncherWindowViewModelTests.cs

@@ -160,6 +160,28 @@ public sealed class LauncherWindowViewModelTests
         Assert.Equal("Headless session started for +Acdream.", viewModel.OperationStatus);
     }
 
+    [Fact]
+    public async Task AccountGuiSelectWorksWithoutAnyCachedCharacter()
+    {
+        using var orchestrator = new FakeLauncherOrchestrator
+        {
+            IncludeCharacter = false,
+        };
+        using var viewModel = CreateInitialized(orchestrator);
+        SelectAccount(viewModel);
+
+        Assert.Empty(viewModel.SelectedNode!.Children);
+        Assert.True(viewModel.CanLaunchAccountGuiSelect);
+        await viewModel.LaunchAccountGuiSelectCommand.ExecuteAsync();
+
+        Assert.Equal(
+            ("Local ACE", "testaccount", (string?)null, LaunchMode.GuiSelect),
+            orchestrator.LaunchRequest);
+        Assert.Equal(
+            "Character-select session started for testaccount.",
+            viewModel.OperationStatus);
+    }
+
     [Fact]
     public async Task ProbeUsesTheSelectedAccountAndRunningAccountDisablesIt()
     {
@@ -201,6 +223,25 @@ public sealed class LauncherWindowViewModelTests
         Assert.Contains("parked at L1", viewModel.GuiLaunchDisabledReason, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void MissingCoDeployedHostReasonIsVisibleForCharacterActions()
+    {
+        using var orchestrator = new FakeLauncherOrchestrator
+        {
+            AccountLaunchCapability = LauncherCapability.Unavailable(
+                "The co-deployed host is missing; reinstall or update the client."),
+        };
+        using var viewModel = CreateInitialized(orchestrator);
+        SelectCharacter(viewModel);
+
+        Assert.False(viewModel.CanLaunchGui);
+        Assert.False(viewModel.CanLaunchHeadless);
+        Assert.True(viewModel.ShowGuiLaunchDisabledReason);
+        Assert.True(viewModel.ShowHeadlessLaunchDisabledReason);
+        Assert.Contains("missing", viewModel.GuiLaunchDisabledReason, StringComparison.Ordinal);
+        Assert.Contains("missing", viewModel.HeadlessLaunchDisabledReason, StringComparison.Ordinal);
+    }
+
     [Fact]
     public async Task LaunchErrorAndCancellationBecomeSafeVisibleState()
     {
@@ -254,6 +295,36 @@ public sealed class LauncherWindowViewModelTests
         Assert.False(dialog.IsOpen);
     }
 
+    [Fact]
+    public void ModalShellsBlockBackgroundCommandsAndAreMutuallyExclusive()
+    {
+        using var orchestrator = new FakeLauncherOrchestrator();
+        using var viewModel = CreateInitialized(orchestrator);
+
+        Assert.True(viewModel.AddServerCommand.CanExecute(null));
+        viewModel.FirstRunWizardShell.OpenCommand.Execute(null);
+        Assert.True(viewModel.IsModalOpen);
+        Assert.False(viewModel.AddServerCommand.CanExecute(null));
+        Assert.False(viewModel.UpdatePromptShell.OpenCommand.CanExecute(null));
+        Assert.False(Assert.Single(viewModel.Sessions).StopCommand.CanExecute(null));
+
+        // ICommand.Execute cannot bypass the modal gate.
+        viewModel.AddServerCommand.Execute(null);
+        Assert.False(viewModel.EditorDialog.IsOpen);
+        Assert.Null(orchestrator.AddedServer);
+
+        viewModel.CloseActiveModal();
+        Assert.False(viewModel.IsModalOpen);
+        Assert.True(viewModel.AddServerCommand.CanExecute(null));
+
+        viewModel.AddServerCommand.Execute(null);
+        Assert.True(viewModel.EditorDialog.IsOpen);
+        Assert.False(viewModel.FirstRunWizardShell.OpenCommand.CanExecute(null));
+        Assert.False(viewModel.ClearFinishedSessionsCommand.CanExecute(null));
+        viewModel.CloseActiveModal();
+        Assert.False(viewModel.EditorDialog.IsOpen);
+    }
+
     [Fact]
     public async Task ActiveSessionStopAndFinishedSessionClearUseCoreOwnership()
     {
@@ -320,6 +391,10 @@ public sealed class LauncherWindowViewModelTests
 
         public LauncherCapability ProbeCapability { get; set; } = LauncherCapability.Available;
 
+        public LauncherCapability? AccountLaunchCapability { get; set; }
+
+        public bool IncludeCharacter { get; init; } = true;
+
         public LauncherSessionSnapshot Session { get; set; } = CreateSession();
 
         public Func<CancellationToken, Task<LauncherSessionSnapshot>>? LaunchHandler { get; set; }
@@ -344,7 +419,7 @@ public sealed class LauncherWindowViewModelTests
 
         public (LaunchMode Mode, IReadOnlyList<string> Plugins, IReadOnlyList<string> Commands)? SettingsUpdate { get; private set; }
 
-        public (string Server, string Account, string Character, LaunchMode Mode)? LaunchRequest { get; private set; }
+        public (string Server, string Account, string? Character, LaunchMode Mode)? LaunchRequest { get; private set; }
 
         public (string Server, string Account)? ProbeRequest { get; private set; }
 
@@ -362,6 +437,12 @@ public sealed class LauncherWindowViewModelTests
         public LauncherCapability GetLaunchCapability(LaunchMode mode) =>
             Platform.ForLaunchMode(mode);
 
+        public LauncherCapability GetAccountLaunchCapability(
+            string serverName,
+            string accountName,
+            LaunchMode mode) =>
+            AccountLaunchCapability ?? GetLaunchCapability(mode);
+
         public LauncherCapability GetProbeCapability(string serverName, string accountName) =>
             ProbeCapability;
 
@@ -428,7 +509,7 @@ public sealed class LauncherWindowViewModelTests
         public Task<LauncherSessionSnapshot> LaunchAsync(
             string serverName,
             string accountName,
-            string characterName,
+            string? characterName,
             LaunchMode mode,
             CancellationToken cancellationToken = default)
         {
@@ -481,7 +562,7 @@ public sealed class LauncherWindowViewModelTests
                 Error: null,
                 CreatedAt: DateTimeOffset.UnixEpoch);
 
-        private static LauncherServerSnapshot CreateServerSnapshot() => new(
+        private LauncherServerSnapshot CreateServerSnapshot() => new(
             "Local ACE",
             "127.0.0.1",
             9000,
@@ -489,18 +570,21 @@ public sealed class LauncherWindowViewModelTests
                 new LauncherAccountSnapshot(
                     "Local ACE",
                     "testaccount",
-                    [
-                        new LauncherCharacterSnapshot(
-                            "Local ACE",
-                            "testaccount",
-                            "+Acdream",
-                            "0x5000000A",
-                            LaunchMode.GuiSelect,
-                            ["Existing.Plugin"],
-                            ["/tell someone, ready"],
-                            HasRunningSession: true,
-                            SessionStatus: "Connected."),
-                    ],
+                    IncludeCharacter
+                        ?
+                        [
+                            new LauncherCharacterSnapshot(
+                                "Local ACE",
+                                "testaccount",
+                                "+Acdream",
+                                "0x5000000A",
+                                LaunchMode.GuiSelect,
+                                ["Existing.Plugin"],
+                                ["/tell someone, ready"],
+                                HasRunningSession: true,
+                                SessionStatus: "Connected."),
+                        ]
+                        : [],
                     HasRunningActivity: true,
                     ActivityStatus: "Connected."),
             ]);