fix(conversation): 离屏不丢回复、列表预热 WS 与非阻塞进入聊天

- 后端：文本/转写后 AI 生成改为独立任务，避免断连取消整轮；按需 TTS 等与 WS 改动
- 前端：RealtimeSession 重绑 UI 时恢复流式 buffer；列表 onPressIn/挂载预热、已有会话立即 push
- 同步会话相关类型、i18n、测试与 env/资源等累计改动

Co-authored-by: Cursor <cursoragent@cursor.com>

app-expo/src/features/conversation/hooks.ts

@@ -174,6 +174,8 @@ interface UseRealtimeSessionOptions {
   onTtsSegment?: (payload: TtsSegmentPayload) => void;
   /** 用户发出下一条文本/语音成功后调用，用于恢复接受 TTS 片段（打断后丢弃迟到片段） */
   onTtsPlaybackResume?: () => void;
+  /** 本条发送是否请求了「本轮助手朗读」，用于仅在该轮自动播放 WS TTS */
+  onUserSendTtsPreference?: (requestedTts: boolean) => void;
 }
 
 const MIN_RECORDING_DURATION_SEC = 1;
@@ -192,10 +194,19 @@ interface RealtimeSessionState {
   /** 已发出用户消息，尚未收到助手首段流式文本（用于「正在回复」气泡） */
   awaitingAssistantReply: boolean;
   error: string | null;
-  sendText: (text: string) => void;
-  sendVoiceMessage: (uri: string, durationMs: number) => Promise<boolean>;
+  sendText: (text: string, options?: { ttsThisTurn?: boolean }) => void;
+  sendVoiceMessage: (
+    uri: string,
+    durationMs: number,
+    options?: { ttsThisTurn?: boolean },
+  ) => Promise<boolean>;
   sendEndConversation: () => void;
   sendTtsCancel: () => void;
+  requestAssistantSegmentTts: (body: {
+    assistantMessageId: string;
+    segmentIndex: number;
+    segmentText?: string;
+  }) => boolean;
 }
 
 export function useRealtimeSession({
@@ -203,6 +214,7 @@ export function useRealtimeSession({
   enabled = true,
   onTtsSegment,
   onTtsPlaybackResume,
+  onUserSendTtsPreference,
 }: UseRealtimeSessionOptions): RealtimeSessionState {
   const queryClient = useQueryClient();
   const sessionRef = useRef<RealtimeSession | null>(null);
@@ -301,15 +313,17 @@ export function useRealtimeSession({
   }, [conversationId, enabled, queryClient, foregroundResumeGeneration]);
 
   const sendText = useCallback(
-    (text: string) => {
+    (text: string, options?: { ttsThisTurn?: boolean }) => {
       if (!sessionRef.current) return;
 
-      const sent = sessionRef.current.sendText(text);
+      const sent = sessionRef.current.sendText(text, options);
       if (!sent) {
         setError('消息发送失败，连接未就绪');
         return;
       }
 
+      onUserSendTtsPreference?.(options?.ttsThisTurn === true);
+
       setAwaitingAssistantReply(true);
       onTtsPlaybackResume?.();
 
@@ -342,11 +356,15 @@ export function useRealtimeSession({
         },
       );
     },
-    [conversationId, queryClient, onTtsPlaybackResume],
+    [conversationId, queryClient, onTtsPlaybackResume, onUserSendTtsPreference],
   );
 
   const sendVoiceMessage = useCallback(
-    async (uri: string, durationMs: number): Promise<boolean> => {
+    async (
+      uri: string,
+      durationMs: number,
+      options?: { ttsThisTurn?: boolean },
+    ): Promise<boolean> => {
       const session = sessionRef.current;
       if (!session) return false;
 
@@ -363,12 +381,15 @@ export function useRealtimeSession({
           clientSegmentId: `${voiceSessionId}-0`,
           isLast: true,
           duration: durationSec,
+          ttsThisTurn: options?.ttsThisTurn,
         });
         if (!sent) {
           setError('语音发送失败，连接未就绪');
           return false;
         }
 
+        onUserSendTtsPreference?.(options?.ttsThisTurn === true);
+
         setAwaitingAssistantReply(true);
         const localId = `pending_voice_${Date.now()}`;
         await voiceSegmentStore.recordSentSegment({
@@ -413,7 +434,7 @@ export function useRealtimeSession({
         return false;
       }
     },
-    [conversationId, queryClient, onTtsPlaybackResume],
+    [conversationId, queryClient, onTtsPlaybackResume, onUserSendTtsPreference],
   );
 
   const sendEndConversation = useCallback(() => {
@@ -424,6 +445,15 @@ export function useRealtimeSession({
     sessionRef.current?.sendTtsCancel();
   }, []);
 
+  const requestAssistantSegmentTts = useCallback(
+    (body: {
+      assistantMessageId: string;
+      segmentIndex: number;
+      segmentText?: string;
+    }) => sessionRef.current?.requestAssistantSegmentTts(body) ?? false,
+    [],
+  );
+
   return {
     connectionState,
     streamingMessage,
@@ -433,5 +463,6 @@ export function useRealtimeSession({
     sendVoiceMessage,
     sendEndConversation,
     sendTtsCancel,
+    requestAssistantSegmentTts,
   };
 }