fix: add recent dialogue loader to conversation store

qingjian_cs/app/store.py

@@ -249,3 +249,60 @@ class ConversationStore:
             conn.commit()
         finally:
             conn.close()
+
+    def get_recent_dialogue(self, customer_key: str, limit: int = 24) -> list[dict[str, Any]]:
+        """
+        拉取最近对话（按 customer_key 隔离，即 店铺+客户）。
+        仅返回 customer_message / assistant_message 两类事件。
+        """
+        t_e = self.events_table
+        n = max(1, int(limit))
+        conn = self._conn()
+        try:
+            with conn.cursor() as c:
+                if self.backend == "mysql":
+                    c.execute(
+                        f"""
+                        SELECT event, payload_json
+                        FROM {t_e}
+                        WHERE customer_key=%s
+                          AND event IN ('customer_message','assistant_message')
+                        ORDER BY id DESC
+                        LIMIT %s
+                        """,
+                        (customer_key, n),
+                    )
+                else:
+                    c.execute(
+                        f"""
+                        SELECT event, payload_json
+                        FROM {t_e}
+                        WHERE customer_key=?
+                          AND event IN ('customer_message','assistant_message')
+                        ORDER BY id DESC
+                        LIMIT ?
+                        """,
+                        (customer_key, n),
+                    )
+                rows = c.fetchall() or []
+
+            out: list[dict[str, Any]] = []
+            for row in reversed(rows):
+                if isinstance(row, dict):
+                    ev = str(row.get("event", "") or "")
+                    raw = row.get("payload_json")
+                else:
+                    ev = str(row[0] or "")
+                    raw = row[1]
+                try:
+                    payload = raw if isinstance(raw, dict) else json.loads(raw or "{}")
+                except Exception:
+                    payload = {}
+                msg = str(payload.get("msg", "") or "").strip()
+                if not msg:
+                    continue
+                role = "user" if ev == "customer_message" else "assistant"
+                out.append({"role": role, "text": msg})
+            return out
+        finally:
+            conn.close()