perf(memory): truncate profile list fields to 5 items in get_end_user_info response

Limit role, domain, expertise, and interests arrays to MAX_PROFILE_LIST_SIZE (5) entries when returning end user info to reduce response payload size.

api/app/services/user_memory_service.py

@@ -401,12 +401,21 @@ class UserMemoryService:
             # 构建响应数据（转换时间为毫秒时间戳）
             # 将 meta_data 中的 profile、knowledge_tags、behavioral_hints 平铺到顶层
             meta = end_user_info_record.meta_data or {}
+
+            # profile 列表字段截断：只返回前 MAX_PROFILE_LIST_SIZE 条（按时间从新到旧）
+            MAX_PROFILE_LIST_SIZE = 5
+            profile = meta.get("profile")
+            if isinstance(profile, dict):
+                for key in ("role", "domain", "expertise", "interests"):
+                    if isinstance(profile.get(key), list):
+                        profile[key] = profile[key][:MAX_PROFILE_LIST_SIZE]
+
             response_data = {
                 "end_user_info_id": str(end_user_info_record.id),
                 "end_user_id": str(end_user_info_record.end_user_id),
                 "other_name": end_user_info_record.other_name,
                 "aliases": end_user_info_record.aliases,
-                "profile": meta.get("profile"),
+                "profile": profile,
                 "knowledge_tags": meta.get("knowledge_tags"),
                 "behavioral_hints": meta.get("behavioral_hints"),
                 "created_at": datetime_to_timestamp(end_user_info_record.created_at),