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>

api/app/features/conversation/tts_delivery.py

@@ -9,9 +9,15 @@
 
 from __future__ import annotations
 
-from app.core.cos_url_keys import presign_tts_urls_for_playback
+from app.core.cos_url_keys import (
+    TTS_PRESIGNED_EXPIRES_SEC,
+    extract_cos_object_key_if_owned,
+)
+from app.core.logging import get_logger
 from app.ports.storage import ObjectStorage
 
+logger = get_logger(__name__)
+
 
 def apply_presigned_tts_urls_to_messages(
     messages: list[dict],
@@ -24,5 +30,26 @@ def apply_presigned_tts_urls_to_messages(
         tts = m.get("ttsAudioUrls")
         if not isinstance(tts, list) or not tts:
             continue
-        str_urls = [x for x in tts if isinstance(x, str)]
-        m["ttsAudioUrls"] = presign_tts_urls_for_playback(str_urls, storage)
+        out: list[str] = []
+        for x in tts:
+            if not isinstance(x, str):
+                out.append("")
+                continue
+            s = x.strip()
+            if not s:
+                out.append("")
+                continue
+            key = extract_cos_object_key_if_owned(s)
+            if key:
+                try:
+                    out.append(storage.get_url(key, expires=TTS_PRESIGNED_EXPIRES_SEC))
+                except Exception as exc:
+                    logger.warning(
+                        "presign tts url failed, keeping original url: key={} err={}",
+                        key,
+                        exc,
+                    )
+                    out.append(s)
+            else:
+                out.append(s)
+        m["ttsAudioUrls"] = out