feat(chat): persona decides to buy/walk — auto-finish + tolerance (temper) + resume

The conversation now ENDS when the persona makes a decision (option C), not when the
trainee clicks a button:
- persona_id replies carry {reply, decision(none/buy/walk), mood}; when decision is
  buy/walk the session auto-finishes (won/lost) with a debrief that reveals latent
  details + per-turn 'turning points'.
- personas have a tolerance (1-5, 'temper'): impatient personas walk away fast after
  poor answers (fed via internal.misses on mood<=-1); tough 'wrong text' cases can
  still be won by a strong, gentle response (judge realism).
- trainee 'Finish' button removed; if they leave mid-chat an active session is resumed
  via /chat/resume (continue, not restart). One-shot lock still enforced once decided.
- mock/tests updated: persona deciding buy -> send auto-finishes won.
Rebuilt dist.

frontend/src/api/index.js

@@ -48,6 +48,7 @@ export const api = {
   getPersona: (gid, pid) => request('GET', `/api/groups/${gid}/personas/${pid}`),
   updatePersona: (gid, pid, b) => request('PUT', `/api/groups/${gid}/personas/${pid}`, b),
   chatStart: (gid, pid, scenario) => request('POST', `/api/chat/${gid}/personas/${pid}/chat/start`, scenario || {}),
+  chatResume: (gid, pid) => request('GET', `/api/chat/${gid}/personas/${pid}/chat/resume`),
   chatSend: (gid, pid, text) => request('POST', `/api/chat/${gid}/personas/${pid}/chat/send`, { text }),
   chatFinish: (gid, pid) => request('POST', `/api/chat/${gid}/personas/${pid}/chat/finish`),
   mySessions: () => request('GET', '/api/chat/sessions'),

frontend/src/views/Chat.vue

@@ -37,9 +37,9 @@
         <h2 style="margin:0">{{ persona ? persona.name : '...' }}</h2>
         <span class="badge" :class="persona && persona.channel">{{ persona ? persona.channel : '' }}</span>
         <span class="muted" v-if="persona">{{ persona.profession }} · {{ persona.age_group }}</span>
-        <button class="danger" style="margin-left:auto" @click="finish" :disabled="messages.length === 0 || phase === 'done'">
-          <span v-if="sending" class="spinner" style="margin-right:4px"></span>{{ i18n.t('finish') }}
-        </button>
+        <span v-if="phase === 'done'" class="badge" :class="debrief && debrief.outcome">
+          {{ debrief && debrief.outcome === 'won' ? i18n.t('won') : i18n.t('lost') }}
+        </span>
       </div>
 
       <!-- Chat thread -->
@@ -102,7 +102,6 @@ const messages = ref([])
 const text = ref('')
 const sending = ref(false)
 const debrief = ref(null)
-const taskText = ref('')
 const sessionId = ref(null)
 const picked = ref('social')
 
@@ -123,13 +122,33 @@ async function begin() {
   phase.value = 'chat'
   const res = await api.chatStart(gid, pid, { scenario: picked.value })
   sessionId.value = res.session.id
-  if (res.session.task) taskText.value = res.session.task
   messages.value = res.session.messages || []
   if (messages.value.length) scrollDown()
 }
 
 onMounted(async () => {
   persona.value = (await api.getPersona(gid, pid)).persona
+  // Resume: if there's an unfinished session for this persona, continue it instead of restarting.
+  try {
+    const r = await api.chatResume(gid, pid)
+    sessionId.value = r.session.id
+    messages.value = r.session.messages || []
+    if (messages.value.length && !r.session.debrief) {
+      phase.value = 'chat'
+      // re-derive which scenario was active
+      const sc = scenarios.find((s) => s.id === r.scenario)
+      if (sc) picked.value = r.scenario
+      // if session has a debrief already, it's done
+    } else if (r.session.debrief) {
+      debrief.value = r.session.debrief
+      messages.value = r.session.messages || []
+      phase.value = 'done'
+    }
+    if (messages.value.length) scrollDown()
+  } catch (e) {
+    // no active session -> show the scenario picker
+    phase.value = 'pick'
+  }
 })
 
 async function send() {
@@ -139,6 +158,10 @@ async function send() {
     const res = await api.chatSend(gid, pid, text.value.trim())
     messages.value = res.messages
     text.value = ''
+    if (res.finished) {
+      debrief.value = res.debrief || null
+      phase.value = 'done'
+    }
     scrollDown()
   } catch (e) {
     alert(e.message)
@@ -147,21 +170,6 @@ async function send() {
   }
 }
 
-async function finish() {
-  if (!confirm(i18n.t('finish') + '?')) return
-  sending.value = true
-  try {
-    const res = await api.chatFinish(gid, pid)
-    debrief.value = res.debrief
-    messages.value = res.session.messages
-    phase.value = 'done'
-  } catch (e) {
-    alert(e.message)
-  } finally {
-    sending.value = false
-  }
-}
-
 const FIELD_LABELS = {
   name: 'ชื่อ', tier: 'ระดับ', difficulty: 'ความยาก', profession: 'อาชีพ',
   age_group: 'ช่วงอายุ', location: 'พื้นที่', income: 'รายได้', budget: 'งบประมาณ',