feat: release chat and mindspace UI updates

src/components/ChatView.tsx

@@ -72,6 +72,7 @@ export function ChatView({
   }, [sidebarOpen, onSidebarOpen]);
 
   const busy = chatState === 'streaming' || chatState === 'loading' || chatState === 'connecting';
+  const showHomeWelcome = messages.length === 0;
 
   const handleSelectSession = (sessionId: string) => {
     void switchSession(sessionId);
@@ -85,7 +86,7 @@ export function ChatView({
 
   const sessionTitle = session
     ? getSessionDisplayName(session)
-    : chatState === 'connecting'
+    : chatState === 'idle'
       ? '新对话'
       : '连接中…';
 
@@ -128,8 +129,8 @@ export function ChatView({
         onDelete={(sessionId) => void deleteSession(sessionId)}
       />
 
-      <div className="app">
-        <header className="header">
+      <div className={`app${showHomeWelcome ? ' app-home' : ''}`}>
+        <header className={`header${showHomeWelcome ? ' header-home' : ''}`}>
           <div className="header-left">
             <button
               type="button"