a transcript with nothing in it can say nothing

"Send a message to start" is right on the chat screen and wrong under a setup
card that already says what to do — it contradicts the Start button above it and
takes 200px of height doing so, which is what squeezed the new-commander pane
into a scroller a third of the panel tall.

`emptyState` is optional and three-valued on purpose: undefined keeps the
default, a node replaces it, null shows nothing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/workspaces/officerdev/src/apps/Chat/EmbeddableChat/EmbeddableChat.tsx

@@ -1,3 +1,4 @@
+import type { ReactNode } from 'react';
 import type { UseChatType } from '../../../hooks/useChat';
 import { useEmbeddableChat } from './useEmbeddableChat';
 import { MessageList } from '../components/MessageList';
@@ -5,6 +6,14 @@ import { InputArea } from '../components/InputArea';
 
 type EmbeddableChatProps = {
   sessionId?: string;
+  /**
+   * What the transcript shows before there is anything in it. `null` shows nothing.
+   *
+   * The default, "Send a message to start", is true on the chat screen and wrong wherever something else
+   * already explains what to do — a new commander has a setup card and a Start button above it, so the
+   * message contradicts them and takes 200px of height while doing it.
+   */
+  emptyState?: ReactNode;
   /** Which panel this is — see `queue-store`. Absent on the screen, where there is only one chat. */
   panelId?: string;
   initialModel?: string | null;

src/workspaces/officerdev/src/apps/Chat/EmbeddableChat/useEmbeddableChat.ts

@@ -1,3 +1,4 @@
+import type { ReactNode } from 'react';
 import type { KeyboardEvent } from 'react';
 import { useState, useRef, useEffect, useCallback } from 'react';
 import { useUserVisibleModels } from 'state/useModels';
@@ -51,6 +52,7 @@ type UseEmbeddableChatParams = {
   contextId?: string;
   /** This session is a commander, per `GET /chat/sessions/:id`. See the note where it is surfaced. */
   isCommander?: boolean;
+  emptyState?: ReactNode;
 };
 
 /**
@@ -622,6 +624,7 @@ export function useEmbeddableChat(params: UseEmbeddableChatParams, onMessageComp
       would lose the brand-new composer, which has no session yet.
     */
     isCommander: params.context === 'command-hq' || params.isCommander === true,
+    emptyState: params.emptyState,
     /*
       Claude's transcript id, which is what a commander is keyed on everywhere — the Command HQ row, the
       record of what it spawned, the delete cascade. `sessionId` above is OFFICER's handle for the same

src/workspaces/officerdev/src/apps/Chat/components/MessageList.tsx

@@ -107,11 +107,17 @@ export const MessageList = ({ manager }: MessageListProps) => {
         </div>
       )}
       <div ref={scrollViewportRef} className="h-full overflow-y-auto">
-        {rows.length === 0 && !isGenerating && (
+        {rows.length === 0 &&
+          !isGenerating &&
+          // `undefined` means nobody said, so keep the default. `null` means "show nothing", which is what
+          // a screen that already explains itself above the transcript passes.
+          (manager.emptyState !== undefined ? (
+            manager.emptyState
+          ) : (
             <div className="flex items-center justify-center h-full min-h-[200px] text-muted-foreground text-sm">
               Send a message to start
             </div>
-        )}
+          ))}
         {rows.length > 0 && (
           <ToolOpenProvider>
             <div className="relative w-full" style={{ height: virtualizer.getTotalSize() }}>

src/workspaces/officerdev/src/apps/CommandHQ/CommandHqDetail.tsx

@@ -365,6 +365,7 @@ function NewCommander({
           !started && !ready ? { reason: !name.trim() ? 'Name it first…' : 'Choose a working directory first…' } : false
         }
         className={!started ? 'shrink-0' : 'min-h-0 flex-1'}
+        {...(!started ? { emptyState: null } : {})}
       />
       <DirPickerModal open={pickerOpen} onClose={() => setPickerOpen(false)} onSelect={setCwd} />
     </div>