feat(practice): run realtime practice on App-Plus through renderjs

App-Plus has no WebRTC or getUserMedia in the logic layer, so realtime
practice was H5-only and the native entry had to advertise a record-then-
transcribe downgrade.

Move the media/WebRTC engine into `realtime-browser-engine.js` and drive it
from `RealtimePracticeAppBridge.vue`, whose renderjs script runs inside the
system WebView where those APIs do exist. The logic layer keeps the
authenticated calls: SDP exchange and `search_knowledge` tool invocation stay
server-proxied, so the access token is never handed to the view layer. Both
sides talk over the renderjs bridge only in session payloads the server
already assembled.

Verified against a real App build (`app-renderjs.js` holds RTCPeerConnection
and getUserMedia; `app-service.js` holds the SDP endpoint, renderjs side has
zero hits). Microphone permission, live transcription, remote playback,
foreground/background switching and disconnect fallback still require Android
and iOS device verification.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

mobile-uni/src/pages/user/practice/index.vue

@@ -485,6 +485,18 @@
       <button class="secondary-button" @click="openPracticeHistory">查看训练记录</button>
       <button class="primary-button tabbar-safe-action" :disabled="!canStartPractice || busy" @click="start(selectedScenarioId)">再练一次</button>
     </view>
+
+    <!-- #ifdef APP-PLUS -->
+    <RealtimePracticeAppBridge
+      ref="realtimeAppBridge"
+      @status="handleRealtimeStatus"
+      @trainee-transcript="handleRealtimeTraineeTranscript"
+      @customer-transcript="handleRealtimeCustomerTranscript"
+      @audio-playback-blocked="handleRealtimeAudioPlaybackBlocked"
+      @terminated="handleRealtimeTerminated"
+      @error="handleRealtimeError"
+    />
+    <!-- #endif -->
   </view>
 </template>
 
@@ -492,6 +504,7 @@
 import { computed, nextTick, ref } from 'vue';
 import { onHide, onShow, onUnload } from '@dcloudio/uni-app';
 import ChatComposer from '@/components/chat/ChatComposer.vue';
+import RealtimePracticeAppBridge from '@/components/practice/RealtimePracticeAppBridge.vue';
 import type {
   PracticeFinishResponse,
   PracticePrepCard,
@@ -513,7 +526,7 @@ import { searchKnowledge } from '@/services/knowledge';
 import { resetPageScroll } from '@/services/navigation';
 import { ensureEmployeePosition } from '@/services/position';
 import { chooseSpeechAudio, createSpeechPlaybackController, customerVoiceProfile, measureAudioDuration, MENTOR_VOICE_PROFILE, normalizeOssId, transcribeSpeechCapture, transcribeSpeechFile } from '@/services/speech';
-import { startSpeechCapture } from '@/services/speech-capture';
+import { isNativeAppRuntime, startSpeechCapture } from '@/services/speech-capture';
 import type { SpeechCapture, SpeechCaptureSession } from '@/services/speech-capture';
 import { createPageRequestScope, currentAccountKey, type RequestScopeTicket } from '@/services/request-scope';
 import { createRealtimePracticeController, createRealtimeSession, fetchRealtimePersonas, invokeRealtimeTool, type RealtimePersonaOption } from '@/services/realtime-practice';
@@ -572,6 +585,11 @@ const realtimeAudioBlocked = ref(false);
 const realtimeSessionId = ref('');
 const realtimePersonaOptions = ref<RealtimePersonaOption[]>([]);
 const selectedRealtimePersonaId = ref(typeof storedRealtimePersona === 'string' ? storedRealtimePersona : '');
+const realtimeAppBridge = ref<{
+  start: (sessionUpdate: Record<string, unknown>, sessionId?: string) => Promise<void>;
+  stop: () => void;
+  resumeAudio: () => Promise<boolean>;
+} | null>(null);
 const growthDetailsExpanded = ref(false);
 const assignments = ref<PracticeAssignment[]>([]);
 const practiceHistory = ref<PracticeRecord[]>([]);
@@ -1010,34 +1028,40 @@ const appendTurn = (role: PracticeRole, text?: string, emotion = 0, synthesizeCu
   scrollThreadToBottom();
 };
 
+const handleRealtimeStatus = (nextStatus: typeof realtimeStatus.value) => {
+  realtimeStatus.value = nextStatus;
+};
+const handleRealtimeTraineeTranscript = (text: string) => {
+  if (realtimeActive.value) appendTurn('trainee', text);
+};
+const handleRealtimeCustomerTranscript = (text: string) => {
+  if (realtimeActive.value) appendTurn('customer', text, 0, false);
+};
+const handleRealtimeAudioPlaybackBlocked = (blocked: boolean) => {
+  if (realtimeActive.value) realtimeAudioBlocked.value = blocked;
+};
+const handleRealtimeTerminated = () => {
+  if (!realtimeActive.value) return;
+  realtimeActive.value = false;
+  realtimeStatus.value = 'idle';
+  realtimeAudioBlocked.value = false;
+  realtimeSessionId.value = '';
+  sessionId.value = '';
+  activeAssignmentId.value = undefined;
+  status.value = 'idle';
+};
+const handleRealtimeError = (text: string) => {
+  if (realtimeActive.value) message.value = text;
+};
 const realtimePractice = createRealtimePracticeController({
-  onStatus: (nextStatus) => {
-    realtimeStatus.value = nextStatus;
-  },
-  onTraineeTranscript: (text) => {
-    if (realtimeActive.value) appendTurn('trainee', text);
-  },
-  onCustomerTranscript: (text) => {
-    if (realtimeActive.value) appendTurn('customer', text, 0, false);
-  },
-  onAudioPlaybackBlocked: (blocked) => {
-    if (realtimeActive.value) realtimeAudioBlocked.value = blocked;
-  },
+  onStatus: handleRealtimeStatus,
+  onTraineeTranscript: handleRealtimeTraineeTranscript,
+  onCustomerTranscript: handleRealtimeCustomerTranscript,
+  onAudioPlaybackBlocked: handleRealtimeAudioPlaybackBlocked,
   onToolCall: (callId, name, argsJson) =>
     invokeRealtimeTool(realtimeSessionId.value, callId, name, argsJson).then((res) => res.output),
-  onTerminated: () => {
-    if (!realtimeActive.value) return;
-    realtimeActive.value = false;
-    realtimeStatus.value = 'idle';
-    realtimeAudioBlocked.value = false;
-    realtimeSessionId.value = '';
-    sessionId.value = '';
-    activeAssignmentId.value = undefined;
-    status.value = 'idle';
-  },
-  onError: (text) => {
-    if (realtimeActive.value) message.value = text;
-  }
+  onTerminated: handleRealtimeTerminated,
+  onError: handleRealtimeError
 });
 
 const selectRealtimePersona = (item: RealtimePersonaOption) => {
@@ -1062,7 +1086,8 @@ const loadRealtimePersonas = async (request: RequestScopeTicket = requests.begin
 
 const stopRealtime = () => {
   if (!realtimeActive.value && realtimeStatus.value === 'idle') return;
-  realtimePractice.stop();
+  if (isNativeAppRuntime()) realtimeAppBridge.value?.stop();
+  else realtimePractice.stop();
   realtimeActive.value = false;
   realtimeStatus.value = 'idle';
   realtimeAudioBlocked.value = false;
@@ -1093,7 +1118,9 @@ const startRealtime = async () => {
     if (!realtimeActive.value) return;
     realtimeSessionId.value = session.sessionId;
     activeScenarioName.value = session.personaName || '实时陪练';
-    await realtimePractice.start(session.sessionUpdate, session.sessionId);
+    const controller = isNativeAppRuntime() ? realtimeAppBridge.value : realtimePractice;
+    if (!controller) throw new Error('实时语音模块尚未就绪，请稍后重试');
+    await controller.start(session.sessionUpdate, session.sessionId);
     if (!realtimeActive.value) return;
     status.value = 'active';
     message.value = `已连接「${session.personaName}」，请直接开口说话。`;
@@ -1107,7 +1134,8 @@ const startRealtime = async () => {
 };
 
 const resumeRealtimeAudio = async () => {
-  if (await realtimePractice.resumeAudio()) {
+  const controller = isNativeAppRuntime() ? realtimeAppBridge.value : realtimePractice;
+  if (controller && await controller.resumeAudio()) {
     message.value = '已恢复实时语音播放。';
   } else {
     message.value = '仍无法播放实时语音，请确认设备媒体权限后重试。';