fix(conversation): 修复实时会话 TTS/回复被离屏 WS 抢占

- 列表预热仅预取消息缓存，避免后台 WebSocket 覆盖服务端连接
- RealtimeSession UI 回调按 owner 独占，防止 offscreen 覆盖聊天页
- 列表页聚焦时再 prewarm，会话页 TTS 入队优先 base64
- 管线下发 TTS 同时带 audio_base64 与 audio_url；协议说明同步
- 移除 TTS 排查用前后端调试日志，保留错误/告警
- 补充 WS / RealtimeSession / entry-warmup / 播放器相关单测

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

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

@@ -18,6 +18,7 @@ import { conversationKeys } from './query-keys';
 import { takePreparedRealtimeSession } from './prepared-session-registry';
 import {
   type ErrorCallback,
+  type RealtimeSessionUiOwner,
   type StreamingTextCallback,
   type TtsSegmentPayload,
   type RealtimeSession,
@@ -219,6 +220,9 @@ export function useRealtimeSession({
 }: UseRealtimeSessionOptions): RealtimeSessionState {
   const queryClient = useQueryClient();
   const sessionRef = useRef<RealtimeSession | null>(null);
+  const uiOwnerRef = useRef<RealtimeSessionUiOwner>(
+    Symbol('conversation-screen-ui'),
+  );
   const uiRef = useRef({
     handleStreamingText: (() => {}) as StreamingTextCallback,
     handleError: (() => {}) as ErrorCallback,
@@ -300,20 +304,23 @@ export function useRealtimeSession({
       prepared,
     );
 
-    session.attachUiCallbacks({
-      onStreamingText: (text, isComplete) => {
-        uiRef.current.handleStreamingText(text, isComplete);
+    session.attachUiCallbacks(
+      {
+        onStreamingText: (text, isComplete) => {
+          uiRef.current.handleStreamingText(text, isComplete);
+        },
+        onTtsSegment: (payload) => uiRef.current.onTtsSegment?.(payload),
+        onError: (message, code) => uiRef.current.handleError(message, code),
+        onStateChange: setConnectionState,
       },
-      onTtsSegment: (payload) => uiRef.current.onTtsSegment?.(payload),
-      onError: (message, code) => uiRef.current.handleError(message, code),
-      onStateChange: setConnectionState,
-    });
+      uiOwnerRef.current,
+    );
 
     sessionRef.current = session;
     setConnectionState(session.getConnectionState());
 
     return () => {
-      releaseConversationWsUi(session);
+      releaseConversationWsUi(session, uiOwnerRef.current);
       sessionRef.current = null;
       setConnectionState('disconnected');
       setStreamingMessage(null);