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>

scripts/g2-lb.Caddyfile.active

@@ -0,0 +1,10 @@
+# g2.tkmind.cn 本地发布：仅本机 Mac H5 (:8081)，不经过 105
+:8090 {
+	reverse_proxy 127.0.0.1:8081 {
+		flush_interval -1
+		transport http {
+			read_timeout 0
+			write_timeout 0
+		}
+	}
+}