Design P6: chat.css neu (Praefix .woms-chat, Umschaltung bei 860 px), Fehlerzeile ohne Icon

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/components/chat/ChatThread.jsx

@@ -1,5 +1,4 @@
 import { useEffect, useRef, useState } from 'react'
-import { FaRotateRight } from 'react-icons/fa6'
 import { Button } from '../ui'
 import { PORTAL_URL, chatUploadUrl, getChatMessages, markChatRead, sendChatMessage, teamAuthHeaders } from '../../lib/teamApi'
 import { loadChatComposer } from '../../lib/loadChatComposer'
@@ -119,8 +118,8 @@ export default function ChatThread({ customerId, customerName }) {
     <div className="woms-chat" ref={zoneRef}>
       {error && (
         <div className="flex items-center gap-2 wrap">
-          <span className="muted">{error}</span>
-          <Button variant="ghost" onClick={() => setReloadKey((k) => k + 1)}><FaRotateRight /> Erneut versuchen</Button>
+          <span className="msg err" role="alert">{error}</span>
+          <Button onClick={() => setReloadKey((k) => k + 1)}>Erneut versuchen</Button>
         </div>
       )}
       <div className="chat-messages" ref={boxRef} aria-live="polite" />