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/dev.mjs

@@ -1,11 +1,16 @@
 #!/usr/bin/env node
+// Compatibility entrypoint for the old full-stack startup.
+// Prefer `pnpm dev` for the core app and `pnpm dev:plaza` for Plaza alone.
 import { spawn, execSync } from 'node:child_process';
 import fs from 'node:fs';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
 const root = path.join(path.dirname(fileURLToPath(import.meta.url)), '..');
-const plazaDir = process.env.PLAZA_APP_DIR ?? path.join(root, '../tkmind_go/ui/plaza');
+const defaultPlazaDir = fs.existsSync(path.join(root, '../test-memindplaza/app/plaza/package.json'))
+  ? path.join(root, '../test-memindplaza/app/plaza')
+  : path.join(root, '../tkmind_go/ui/plaza');
+const plazaDir = process.env.PLAZA_APP_DIR ?? defaultPlazaDir;
 const opsDir = path.join(root, 'ops');
 const portalPort = Number(process.env.H5_PORT ?? 8081);
 const vitePort = Number(process.env.VITE_PORT ?? 5173);
@@ -120,7 +125,7 @@ const opsEnv = {
 
 function ensurePlazaApp() {
   if (!fs.existsSync(path.join(plazaDir, 'package.json'))) {
-    throw new Error(`未找到 Plaza Next.js：${plazaDir}`);
+    throw new Error(`未找到 Plaza Next.js：${plazaDir}。请设置 PLAZA_APP_DIR 指向本地 Plaza 源码，例如 ../test-memindplaza/app/plaza`);
   }
 }