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/components/PersonaForm.vue

@@ -87,7 +87,13 @@ const objectionsText = ref('')
 const negLeversText = ref('')
 const busy = ref(false)
 
-function toLines(a) { return Array.isArray(a) ? a.join('\n') : String(a || '') }
+function toLines(a) {
+  if (!a) return ''
+  if (Array.isArray(a)) {
+    return a.map((x) => (typeof x === 'string' ? x : (x && x.description) || (x && x.text) || '')).filter(Boolean).join('\n')
+  }
+  return String(a)
+}
 function fromLines(s) { return s.split('\n').map(x => x.trim()).filter(Boolean) }
 
 watch(() => props.persona, (p) => {
@@ -109,7 +115,7 @@ watch(() => props.persona, (p) => {
 function save() {
   emit('save', {
     ...d,
-    pains: fromLines(painsText.value),
+    pains: fromLines(painsText.value).map((t) => ({ description: t })),
     objections: fromLines(objectionsText.value),
     negotiation_levers: fromLines(negLeversText.value),
   })