Let the Assistant Builder generate launchers without a workspace

app/MindWork AI Studio/Assistants/Builder/AssistantBuilderChatLaunchMetadata.cs

@@ -2,6 +2,10 @@ namespace AIStudio.Assistants.Builder;
 
 internal sealed class AssistantBuilderChatLaunchMetadata
 {
+    /// <summary>
+    /// The workspace the chat is created in. A model leaves this field out for a launcher that
+    /// opens a chat without a workspace, which is why it stays empty rather than null.
+    /// </summary>
     public string WorkspaceName { get; init; } = string.Empty;
     public string? ProviderId { get; init; }
     public string? ProfileId { get; init; }

app/MindWork AI Studio/Assistants/Builder/AssistantBuilderLuaResponse.schema.json

@@ -131,11 +131,9 @@
     "chatLaunch": {
       "type": "object",
       "additionalProperties": false,
-      "required": [
-        "workspace_name"
-      ],
       "properties": {
         "workspace_name": {
+          "description": "Omit this field for a launcher that opens a chat without a workspace.",
           "type": "string",
           "minLength": 1
         },

app/MindWork AI Studio/Assistants/Builder/LuaResponse.Parse.cs

@@ -124,7 +124,12 @@ internal sealed partial class LuaResponse
 
     private static bool IsValidChatLaunchMetadata(AssistantBuilderChatLaunchMetadata? launch)
     {
-        if (launch is null || string.IsNullOrWhiteSpace(launch.WorkspaceName))
+        //
+        // A missing workspace name describes a launcher that opens a chat without a workspace, so
+        // only the launch block itself is mandatory here. Whether the name matches the plugin the
+        // model wrote is decided later, by comparing both.
+        //
+        if (launch is null)
             return false;
 
         if (!IsOptionalGuid(launch.ProviderId, allowEmpty: false) ||

app/MindWork AI Studio/Tools/Services/AssistantBuilderChatLaunchRequest.cs

@@ -3,7 +3,7 @@ namespace AIStudio.Tools.Services;
 /// <summary>
 /// The chat a direct chat launcher tile opens, as chosen in the Assistant Builder.
 /// </summary>
-/// <param name="WorkspaceName">The workspace the chat is created in.</param>
+/// <param name="WorkspaceName">The workspace the chat is created in; an empty name opens a chat without a workspace instead.</param>
 /// <param name="ProviderId">The provider to preselect, or null for the chat default.</param>
 /// <param name="ProfileId">The profile to preselect; the empty GUID selects no profile.</param>
 /// <param name="ChatTemplateId">The chat template to preselect; the empty GUID selects none.</param>

app/MindWork AI Studio/Tools/Services/AssistantPluginGenerationService.cs

@@ -358,6 +358,7 @@ public sealed class AssistantPluginGenerationService(ToolRegistry toolRegistry,
           - Write description as one sentence that says which chat this tile opens and what it is for. Do not describe an input form, a prompt, or a submit button, because a launcher has none.
           - Write all three texts in the language of the approved draft.
           - Do not mention workspace names, provider names, profile names, template names, data source IDs, or tool IDs in any of the three texts.
+          - When the chat launch names no workspace, the tile opens a chat that belongs to no workspace and disappears again. You may say the chat is temporary, but never invent a workspace name.
           - Do not return Markdown, code fences, explanations, or text outside the JSON object.
           """;
 
@@ -512,6 +513,7 @@ public sealed class AssistantPluginGenerationService(ToolRegistry toolRegistry,
               - Explain omitted provider, profile, template, data-source, or tool values as using the normal chat defaults.
               - In the {{TB("Tools")}} section, say what the preselected tools let the chat do and that users may change the selection once the chat is open.
               - Explain the empty profile/template GUID as explicitly selecting no profile/template.
+              - When the ChatLaunch names no workspace, write in the {{TB("Workspace")}} section that the tile opens a chat without a workspace: it is kept among the temporary chats and is deleted by the maintenance the user configured for them. Never invent a workspace name.
               - Do not propose UI components, submit behavior, BuildPrompt, or a plugin SystemPrompt for a chat launcher.
               """;
 
@@ -620,10 +622,11 @@ public sealed class AssistantPluginGenerationService(ToolRegistry toolRegistry,
           - Keep TYPE = "ASSISTANT".
           - Keep the assistant locally managed. DEPLOYED_USING_CONFIG_SERVER must not be true.
           {{builderMetadataRule}}
-          - Set assistant.kind to "CHAT_LAUNCHER" exactly when the revised ASSISTANT table uses LaunchBehavior = "OPEN_WORKSPACE_CHAT_BY_NAME"; otherwise set it to "FORM".
+          - Set assistant.kind to "CHAT_LAUNCHER" exactly when the revised ASSISTANT table uses LaunchBehavior = "OPEN_WORKSPACE_CHAT_BY_NAME" or "OPEN_TEMPORARY_CHAT"; otherwise set it to "FORM".
           - For a form assistant, include system_prompt, submit_text, and allow_ai_studio_profiles in the JSON assistant object and omit launch. Include tool_ids exactly when the revised ASSISTANT table carries ToolIds.
           - Change ASSISTANT.ToolIds only when the requested change asks for it. Use only tool IDs from the "Available tools" list in the plugin context for tools you add; never invent an ID. Drop the field entirely rather than writing an empty list.
-          - For a chat launcher, include launch with the exact WorkspaceName and optional ProviderId, ProfileId, ChatTemplateId, DataSourceIds, and ToolIds values from the revised ASSISTANT table; omit system_prompt, submit_text, and allow_ai_studio_profiles.
+          - For a chat launcher, include launch with the optional ProviderId, ProfileId, ChatTemplateId, DataSourceIds, and ToolIds values from the revised ASSISTANT table; omit system_prompt, submit_text, and allow_ai_studio_profiles. Include workspace_name with the exact WorkspaceName exactly when the table uses OPEN_WORKSPACE_CHAT_BY_NAME, and omit it for OPEN_TEMPORARY_CHAT.
+          - Keep the LaunchBehavior a launcher already has unless the requested change asks to add or drop its workspace. OPEN_WORKSPACE_CHAT_BY_NAME requires a WorkspaceName, and OPEN_TEMPORARY_CHAT must not carry one.
           - A chat launcher must not include SystemPrompt, SubmitText, AllowProfiles, BuildPrompt, or UI in its ASSISTANT table.
           - Preserve an empty profile or template GUID when it explicitly means no profile or no template. Do not emit empty provider or data-source GUIDs.
           - Preserve existing behavior unless the requested change explicitly modifies it.
@@ -757,8 +760,11 @@ public sealed class AssistantPluginGenerationService(ToolRegistry toolRegistry,
         if (launch is null)
             return true;
 
-        if (string.IsNullOrWhiteSpace(launch.WorkspaceName) ||
+        //
-            !IsOptionalGuid(launch.ProviderId, allowEmpty: false) ||
+        // No workspace name is a choice rather than a gap: the launcher then opens a chat that
+        // belongs to no workspace. Only the remaining fields have a shape to check.
+        //
+        if (!IsOptionalGuid(launch.ProviderId, allowEmpty: false) ||
             !IsOptionalGuid(launch.ProfileId, allowEmpty: true) ||
             !IsOptionalGuid(launch.ChatTemplateId, allowEmpty: true))
             return false;