Add smart ACK provider for WeChat MP replies

Replace fixed ackText with a rule-based AckProvider that picks
response templates by message type and intent (translate, summary,
rewrite, poster, ppt, mindmap, code, search, schedule). Pure sync,
zero I/O, auto-falls back to config.ackText on any error.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/ChatPanel.tsx

@@ -325,6 +325,7 @@ export function ChatPanel({
           streaming={chatState === 'streaming'}
           onAvatarClick={compact ? undefined : openAvatarPicker}
           onSaveAsPage={(message) => setPageSource(message)}
+          publishUserId={user?.id}
           publishUsername={user?.username}
           compact={compact}
         />