feat(desktop): empty-state for empty conversation

apps/desktop/src/pages/ConversationPage.tsx

@@ -6,6 +6,7 @@ import { useParams } from 'react-router-dom';
 
 import { ConversationHeader } from '../components/ConversationHeader';
 import { EmojiPicker } from '../components/EmojiPicker';
+import { EmptyState } from '../components/EmptyState';
 import { ForwardDialog } from '../components/ForwardDialog';
 import { GroupInfoPanel } from '../components/GroupInfoPanel';
 import {
@@ -17,6 +18,7 @@ import {
   PollIcon,
   ReplyIcon,
   SearchIcon,
+  SendIcon,
   SmileIcon,
   SpinnerIcon,
   XIcon,
@@ -670,7 +672,13 @@ export function ConversationPage() {
         ) : error ? (
           <Banner>{error}</Banner>
         ) : messages.length === 0 ? (
-          <p className="text-center text-sm text-fg-muted">…</p>
+          <EmptyState
+            icon={<SendIcon className="h-8 w-8" />}
+            title={t('app:chats.conv_empty_title', { defaultValue: 'Sag Hallo 👋' })}
+            description={t('app:chats.conv_empty_desc', {
+              defaultValue: 'Hier ist noch nichts. Schreibe die erste Nachricht.',
+            })}
+          />
         ) : (
           <ul className="space-y-0.5">
             {displayCount < messages.length && (