fix(ui): no raw JSON on Training list, pain no longer [object Object], add Chat button on GroupEdit, drop facebook/line from persona

- list_groups returns lightweight summaries (id/title/status/persona_count + product) —
  never the full personas array, so Training no longer shows a long JSON blob.
- PersonaForm toLines extracts .description/.text from pain/objection objects (fixes
  '[object Object]'); save re-wraps pains as {description}.
- GroupEdit persona cards get a 'แชท' (MessageSquare) button so you can start chatting
  right where you land after creating (chat was only on Personas page before).
- channel: default neutral 'social', removed facebook/line validation + removed from
  revealable_view (scenario now sets the tone, not fb/line).
All 9 backend suites pass. Rebuilt dist.

frontend/src/views/GroupEdit.vue

@@ -43,7 +43,12 @@
           </div>
           <div class="muted">{{ p.profession }} · {{ p.age_group }} · {{ p.location }}</div>
           <div class="muted">{{ p.personality }}</div>
-          <button class="edit-btn" @click="openEdit(p)"><Pencil :size="15" :stroke-width="1.8" /> {{ i18n.t('edit') }}</button>
+          <div class="row" style="gap:8px;margin-top:auto">
+            <router-link :to="`/groups/${gid}/chat/${p.id}`" style="flex:1;text-decoration:none">
+              <button class="primary" style="width:100%"><MessageSquare :size="16" :stroke-width="1.8" /> {{ i18n.t('chat') }}</button>
+            </router-link>
+            <button class="edit-btn" @click="openEdit(p)"><Pencil :size="15" :stroke-width="1.8" /> {{ i18n.t('edit') }}</button>
+          </div>
         </div>
       </div>
     </div>
@@ -60,7 +65,7 @@
 <script setup>
 import { onMounted, ref } from 'vue'
 import { useRoute } from 'vue-router'
-import { Sparkles, Users, Pencil } from 'lucide-vue-next'
+import { Sparkles, Users, Pencil, MessageSquare } from 'lucide-vue-next'
 import { api } from '../api'
 import { i18n } from '../i18n'
 import PersonaForm from '../components/PersonaForm.vue'