feat(api+app): 对话阶段化、回忆录流水线与客户端会话体验

- DB: segments 用户输入文本（Alembic 0002）
- Chat: 阶段检测/阶段提示/回复限制，编排与访谈/画像 prompts 调整
- Memoir: 忠实度检查 agent，叙事与分类等链路更新
- Core: agent 日志、Alembic 启动、LangChain/日志/配置等
- Story: time_hints；Memory 检索与相关测试
- Expo: 助手头像、会话页与消息拆分、实时会话与文案/i18n
- Docs/scripts/tests: 迁移脚本、LLM JSON/记忆检索文档、新增单测

api/app/features/conversation/history_store.py

@@ -51,7 +51,7 @@ class ConversationHistoryStore:
         try:
             await self._sync_redis_from_db(conversation_id)
         except Exception as exc:
-            logger.warning("conversation history cache sync skipped: %s", exc)
+            logger.warning("conversation history cache sync skipped: {}", exc)
 
     async def record_ai_only_turn(
         self, conversation_id: str, responses: list[str]