Let assistant plugins launch a chat without a workspace

app/MindWork AI Studio/Tools/PluginSystem/Assistants/AssistantChatLaunchConfiguration.cs

@@ -1,4 +1,12 @@
 namespace AIStudio.Tools.PluginSystem.Assistants;
 
+/// <param name="WorkspaceName">The workspace the chat is created in. An empty name means the launcher opens a chat without a workspace, which the app shows as a disappearing chat.</param>
 /// <param name="ToolIds">The tools preselected for the chat, or null when the launcher names none.</param>
-public sealed record AssistantChatLaunchConfiguration(string WorkspaceName, Guid? ProviderId, Guid? ProfileId, Guid? ChatTemplateId, IReadOnlyList<Guid>? DataSourceIds, IReadOnlyList<string>? ToolIds);
+public sealed record AssistantChatLaunchConfiguration(string WorkspaceName, Guid? ProviderId, Guid? ProfileId, Guid? ChatTemplateId, IReadOnlyList<Guid>? DataSourceIds, IReadOnlyList<string>? ToolIds)
+{
+    /// <summary>
+    /// Whether the launcher opens a chat that belongs to no workspace. The missing workspace name is
+    /// the whole condition, so the launch behavior and the written plugin follow from it.
+    /// </summary>
+    public bool OpensTemporaryChat => string.IsNullOrWhiteSpace(this.WorkspaceName);
+}

app/MindWork AI Studio/Tools/PluginSystem/Assistants/AssistantPluginLaunchBehavior.cs

@@ -4,4 +4,5 @@ public enum AssistantPluginLaunchBehavior
 {
     NONE,
     OPEN_WORKSPACE_CHAT_BY_NAME,
+    OPEN_TEMPORARY_CHAT,
 }

app/MindWork AI Studio/Tools/PluginSystem/Assistants/DirectChatLauncherLuaWriter.cs

@@ -165,8 +165,18 @@ public static class DirectChatLauncherLuaWriter
         builder.AppendLine("ASSISTANT = {");
         builder.AppendLine($"    [\"Title\"] = \"{Escape(definition.Title)}\",");
         builder.AppendLine($"    [\"Description\"] = \"{Escape(definition.Description)}\",");
-        builder.AppendLine($"    [\"LaunchBehavior\"] = \"{nameof(AssistantPluginLaunchBehavior.OPEN_WORKSPACE_CHAT_BY_NAME)}\",");
+        //
-        builder.AppendLine($"    [\"WorkspaceName\"] = \"{Escape(definition.Launch.WorkspaceName.Trim())}\",");
+        // The behavior follows from the workspace rather than being tracked next to it. A launcher
+        // without one has no name to write, and the plugin loader rejects a WorkspaceName there, so
+        // the field is left out the same way the optional IDs below are:
+        //
+        if (definition.Launch.OpensTemporaryChat)
+            builder.AppendLine($"    [\"LaunchBehavior\"] = \"{nameof(AssistantPluginLaunchBehavior.OPEN_TEMPORARY_CHAT)}\",");
+        else
+        {
+            builder.AppendLine($"    [\"LaunchBehavior\"] = \"{nameof(AssistantPluginLaunchBehavior.OPEN_WORKSPACE_CHAT_BY_NAME)}\",");
+            builder.AppendLine($"    [\"WorkspaceName\"] = \"{Escape(definition.Launch.WorkspaceName.Trim())}\",");
+        }
 
         //
         // Omitted IDs mean "use the chat defaults", while an empty GUID explicitly selects no

app/MindWork AI Studio/Tools/PluginSystem/Assistants/PluginAssistants.cs

@@ -223,38 +223,61 @@ public sealed class PluginAssistants(bool isInternal, LuaState state, PluginType
         if (launchBehavior is AssistantPluginLaunchBehavior.NONE)
             return true;
 
+        //
+        // Both launch behaviors describe the same chat and differ only in where it is kept, so only
+        // the workspace is read per behavior. Everything else follows below, for both of them:
+        //
+        var workspaceName = string.Empty;
         switch (launchBehavior)
         {
             case AssistantPluginLaunchBehavior.OPEN_WORKSPACE_CHAT_BY_NAME:
                 if (!assistantTable.TryGetValue("WorkspaceName", out var workspaceNameValue) ||
-                    !workspaceNameValue.TryRead<string>(out var workspaceName))
+                    !workspaceNameValue.TryRead<string>(out var configuredWorkspaceName))
                 {
                     message = TB("The ASSISTANT table contains the LaunchBehavior 'OPEN_WORKSPACE_CHAT_BY_NAME' but no valid WorkspaceName.");
                     return false;
                 }
 
-                workspaceName = workspaceName.Trim();
+                workspaceName = configuredWorkspaceName.Trim();
                 if (string.IsNullOrWhiteSpace(workspaceName))
                 {
                     message = TB("The ASSISTANT table contains an empty WorkspaceName for LaunchBehavior 'OPEN_WORKSPACE_CHAT_BY_NAME'.");
                     return false;
                 }
 
-                if (!TryReadOptionalGuid(assistantTable, "ProviderId", false, out var providerId, out message) ||
+                break;
-                    !TryReadOptionalGuid(assistantTable, "ProfileId", true, out var profileId, out message) ||
+
-                    !TryReadOptionalGuid(assistantTable, "ChatTemplateId", true, out var chatTemplateId, out message) ||
+            //
-                    !TryReadOptionalDataSourceIds(assistantTable, out var dataSourceIds, out message) ||
+            // A chat without a workspace has no name to carry, so one written here can only be a
-                    !TryReadOptionalToolIds(assistantTable, out var toolIds, out message))
+            // mistake. We reject it rather than dropping it silently: a misspelled LaunchBehavior
+            // would otherwise turn a workspace launcher into a disappearing one, and the author
+            // would only notice it by the chats going missing.
+            //
+            case AssistantPluginLaunchBehavior.OPEN_TEMPORARY_CHAT:
+                if (assistantTable.TryGetValue("WorkspaceName", out var unexpectedWorkspaceNameValue) &&
+                    unexpectedWorkspaceNameValue.TryRead<string>(out var unexpectedWorkspaceName) &&
+                    !string.IsNullOrWhiteSpace(unexpectedWorkspaceName))
+                {
+                    message = TB("The ASSISTANT table contains a WorkspaceName for LaunchBehavior 'OPEN_TEMPORARY_CHAT'. A chat without a workspace cannot have one.");
                     return false;
+                }
 
-                this.ChatLaunchConfiguration = new(workspaceName, providerId, profileId, chatTemplateId, dataSourceIds, toolIds);
+                break;
-
-                return true;
 
             default:
                 message = TB("The ASSISTANT table contains an unsupported LaunchBehavior value.");
                 return false;
         }
+
+        if (!TryReadOptionalGuid(assistantTable, "ProviderId", false, out var providerId, out message) ||
+            !TryReadOptionalGuid(assistantTable, "ProfileId", true, out var profileId, out message) ||
+            !TryReadOptionalGuid(assistantTable, "ChatTemplateId", true, out var chatTemplateId, out message) ||
+            !TryReadOptionalDataSourceIds(assistantTable, out var dataSourceIds, out message) ||
+            !TryReadOptionalToolIds(assistantTable, out var toolIds, out message))
+            return false;
+
+        this.ChatLaunchConfiguration = new(workspaceName, providerId, profileId, chatTemplateId, dataSourceIds, toolIds);
+        return true;
     }
 
     private static bool TryReadOptionalGuid(LuaTable assistantTable, string fieldName, bool allowEmpty, out Guid? id, out string message)