feat(idea): create group auto-generates personas; channel removed; product->product/idea

Per product-idea focus:
- GroupBuilder: 'สินค้า/บริการ/ไอเดีย' label; removed the channel select (channel is now
  chosen at chat time as a scenario, not at persona create). Create now auto-runs analyze
  so personas are generated immediately (no separate Analyze button).
- GroupEdit: analyze button becomes 'สร้างบุคคลต้นแบบเพิ่มเติม' which APPENDS more personas
  (backend analyze?append=true reuses sales kit + keeps existing instead of replacing).
- i18n product label updated.
- User-journey test asserts append adds personas (15->30) and existing kept.
All 9 backend suites pass. Rebuilt dist.

frontend/dist/assets/layout-dashboard-dl9BywAR.js

@@ -0,0 +1,6 @@
+import{c as t}from"./index-DNAVmyB5.js";/**
+ * @license lucide-vue-next v1.0.0 - ISC
+ *
+ * This source code is licensed under the ISC license.
+ * See the LICENSE file in the root directory of this source tree.
+ */const h=t("layout-dashboard",[["rect",{width:"7",height:"9",x:"3",y:"3",rx:"1",key:"10lvy0"}],["rect",{width:"7",height:"5",x:"14",y:"3",rx:"1",key:"16une8"}],["rect",{width:"7",height:"9",x:"14",y:"12",rx:"1",key:"1hutg5"}],["rect",{width:"7",height:"5",x:"3",y:"16",rx:"1",key:"ldoo1y"}]]);export{h as L};