fix: restore colbert/ + persist after chat

app/api/chat.py

@@ -31,6 +31,7 @@ from app.llm.base import LLMMessage
 from app.llm.factory import get_llm
 from app.models import db
 from app.models.schemas import ChatRequest, ChatResponse
+from app.services.persist import schedule_push
 from app.streaming.events import (
     sse_done,
     sse_error,
@@ -244,4 +245,12 @@ async def _run_agent(
         "citations": final_state.get("citations", []),
     })
 
+    # 9. ⚠️ 关键: 把 session/message 写完 → 调度 persist push (5s debounce).
+    #    不调的话: 写本地 /data/sqlite/app.db → Space 重启 /data 临时卷清空 →
+    #    历史对话全丢. 5s debounce 够合并同一 session 的 user+assistant 写入.
+    try:
+        await schedule_push()
+    except Exception as e:  # noqa: BLE001
+        logger.warning("schedule_push after chat failed: %s", e)
+
     return final_state, events_log