feat(aihr): add coach-hint style regeneration buttons to practice turn

- /turn accepts optional regenerate+style (serious/gentle/detailed/professional);
  regenerate short-circuits before rememberTraineeReply — no round advance,
  no trainee reply write, no scoring impact; only same-round coachHint evidence
  is overwritten
- Style instruction injected into existing LLM turn prompt; LLM missing/failed
  returns original hint with explicit message (no fake data)
- Mobile practice page renders 再严肃/再温柔/更细致/更专业 pills under coach
  hints; success replaces text with a style note, failure toasts and keeps
  original; old clients unaffected (fields appended)

mobile/src/App.vue

@@ -690,6 +690,18 @@
                           <b>{{ practiceTurnDuration(turn.role, index) }}</b>
                         </small>
                       </p>
+                      <div v-if="turn.role === 'coach' && turn.roundIndex !== undefined" class="coach-style-actions">
+                        <small v-if="turn.styleNote" class="coach-style-note">{{ turn.styleNote }}</small>
+                        <button
+                          v-for="option in practiceStyleOptions"
+                          :key="option.key"
+                          type="button"
+                          :disabled="Boolean(practiceRegeneratingKey)"
+                          @click="regeneratePracticeCoach(index, option)"
+                        >
+                          {{ practiceRegeneratingKey === `${index}:${option.key}` ? '调整中' : option.label }}
+                        </button>
+                      </div>
                     </div>
                   </div>
                   <div class="dialogue-memory">
@@ -1243,11 +1255,14 @@ interface RoleHome {
 type PracticeStatus = 'idle' | 'starting' | 'active' | 'submitting' | 'finished';
 type InterviewStatus = PracticeStatus;
 type PracticeRole = 'customer' | 'trainee' | 'coach';
+type PracticeStyleKey = 'serious' | 'gentle' | 'detailed' | 'professional';
 
 interface PracticeTurn {
   role: PracticeRole;
   label: string;
   text: string;
+  roundIndex?: number;
+  styleNote?: string;
 }
 
 interface PracticeStartResponse {
@@ -1267,6 +1282,7 @@ interface PracticePrepCardResponse {
 interface PracticeTurnResponse {
   customerText: string;
   coachHint: string;
+  message?: string;
   emotion?: number;
   trust?: number;
   redFlag?: boolean;
@@ -1693,10 +1709,17 @@ const practiceRoundLabel = computed(() => Math.max(1, Math.min(practiceRoundInde
 const practiceEmotion = ref<number | null>(null);
 const practiceEmotionScore = computed(() => practiceEmotion.value ?? Math.max(45, 76 - practiceRoundIndex.value * 8));
 const waveBars = [12, 20, 28, 16, 34, 24, 18, 32, 22, 30, 14, 26, 18, 35, 20, 12];
+const practiceStyleOptions: { key: PracticeStyleKey; label: string }[] = [
+  { key: 'serious', label: '再严肃' },
+  { key: 'gentle', label: '再温柔' },
+  { key: 'detailed', label: '更细致' },
+  { key: 'professional', label: '更专业' }
+];
 const practiceDraft = ref('');
 const practiceTurns = ref<PracticeTurn[]>([]);
 const practiceResult = ref<PracticeFinishResponse | null>(null);
 const practiceMessage = ref('');
+const practiceRegeneratingKey = ref('');
 const latestPracticeAudioUrl = ref('');
 const latestPracticeAudioOssId = ref<number | null>(null);
 const practicePrepCard = ref<PracticePrepCardResponse | null>(null);
@@ -2952,13 +2975,13 @@ const submitMaterial = async () => {
   }
 };
 
-const appendPracticeTurn = (role: PracticeRole, text: string) => {
+const appendPracticeTurn = (role: PracticeRole, text: string, meta: Partial<PracticeTurn> = {}) => {
   const labels: Record<PracticeRole, string> = {
     customer: 'AI业主',
     trainee: '我的回复',
     coach: 'AI教练'
   };
-  practiceTurns.value.push({ role, label: labels[role], text });
+  practiceTurns.value.push({ role, label: labels[role], text, ...meta });
   if (role === 'customer') {
     void playCustomerVoice(text);
   }
@@ -3017,6 +3040,7 @@ const startMobilePractice = async () => {
   practiceDraft.value = '';
   latestPracticeAudioUrl.value = '';
   latestPracticeAudioOssId.value = null;
+  practiceRegeneratingKey.value = '';
   practiceTurns.value = [];
   practiceRoundIndex.value = 0;
   practiceHelp.value = null;
@@ -3062,6 +3086,7 @@ const submitMobilePractice = async () => {
   const traineeText = practiceDraft.value;
   const traineeAudioUrl = latestPracticeAudioUrl.value;
   const traineeAudioOssId = latestPracticeAudioOssId.value;
+  const submittedRoundIndex = practiceRoundIndex.value;
   practiceDraft.value = '';
   practiceMessage.value = '';
   practiceStatus.value = 'submitting';
@@ -3071,7 +3096,7 @@ const submitMobilePractice = async () => {
       await fetch('/dev-api/api/train/practice/turn', {
         method: 'POST',
         headers: apiHeaders(),
-        body: JSON.stringify({ sessionId: practiceSessionId.value, roundIndex: practiceRoundIndex.value, traineeText, traineeAudioUrl, traineeAudioOssId })
+        body: JSON.stringify({ sessionId: practiceSessionId.value, roundIndex: submittedRoundIndex, traineeText, traineeAudioUrl, traineeAudioOssId })
       })
     );
     latestPracticeAudioUrl.value = '';
@@ -3079,7 +3104,7 @@ const submitMobilePractice = async () => {
     practiceEmotion.value = data.emotion ?? practiceEmotion.value;
     const coachHint = data.redFlag ? data.coachHint || '红线纠偏：先承接诉求，再给责任人与反馈节点。' : data.coachHint;
     if (coachHint) {
-      appendPracticeTurn('coach', coachHint);
+      appendPracticeTurn('coach', coachHint, { roundIndex: submittedRoundIndex });
     }
     if (data.finished) {
       await finishMobilePractice();
@@ -3094,6 +3119,41 @@ const submitMobilePractice = async () => {
   }
 };
 
+const regeneratePracticeCoach = async (index: number, option: { key: PracticeStyleKey; label: string }) => {
+  const turn = practiceTurns.value[index];
+  if (!turn || turn.role !== 'coach' || turn.roundIndex === undefined || practiceRegeneratingKey.value) return;
+  const key = `${index}:${option.key}`;
+  practiceRegeneratingKey.value = key;
+  practiceMessage.value = '';
+  try {
+    const data = await readApi<PracticeTurnResponse>(
+      await fetch('/dev-api/api/train/practice/turn', {
+        method: 'POST',
+        headers: apiHeaders(),
+        body: JSON.stringify({ sessionId: practiceSessionId.value, roundIndex: turn.roundIndex, regenerate: true, style: option.key })
+      })
+    );
+    if (data.message) {
+      throw new Error(data.message);
+    }
+    const coachHint = data.redFlag ? data.coachHint || '红线纠偏：先承接诉求，再给责任人与反馈节点。' : data.coachHint;
+    if (!coachHint) {
+      throw new Error('教练建议重生成失败');
+    }
+    practiceTurns.value[index] = { ...turn, text: coachHint, styleNote: `已按“${option.label}”调整` };
+  } catch (error) {
+    toastMessage.value = error instanceof Error ? error.message : '教练建议调整失败';
+    if (toastTimer) window.clearTimeout(toastTimer);
+    toastTimer = window.setTimeout(() => {
+      toastMessage.value = '';
+    }, 1800);
+  } finally {
+    if (practiceRegeneratingKey.value === key) {
+      practiceRegeneratingKey.value = '';
+    }
+  }
+};
+
 const startCandidateInterview = async () => {
   activeUserPanel.value = 'tasks';
   activeTabLabel.value = '面试';
@@ -6629,6 +6689,37 @@ p {
   background: #f3f8ff;
 }
 
+.coach-style-actions {
+  grid-column: 2;
+  display: flex;
+  flex-wrap: wrap;
+  gap: 7px;
+  align-items: center;
+}
+
+.coach-style-actions button {
+  min-height: 30px;
+  padding: 0 12px;
+  border-radius: 999px;
+  border: 1px solid rgba(87, 154, 255, 0.18);
+  background: #ffffff;
+  color: #3769a9;
+  font-size: 12px;
+  font-weight: 850;
+}
+
+.coach-style-actions button:disabled {
+  opacity: 0.55;
+}
+
+.coach-style-note {
+  width: 100%;
+  color: #4e77ad;
+  font-size: 12px;
+  line-height: 1.25;
+  font-weight: 750;
+}
+
 .practice-wave {
   margin-top: 10px;
   min-height: 34px;