优化缓存命中

server/handlers.js

@@ -7,7 +7,7 @@ const { broadcastToRoom } = require('./ws');
 // 对话历史（内存）
 const conversationHistory = new Map();
 function getHistory(roomId) { if (!conversationHistory.has(roomId)) conversationHistory.set(roomId, []); return conversationHistory.get(roomId); }
-function addToHistory(roomId, role, content) { const h = getHistory(roomId); h.push({ role, content }); if (h.length > 60) conversationHistory.set(roomId, h.slice(-40)); }
+function addToHistory(roomId, role, content) { var h = getHistory(roomId); h.push({ role: role, content: content }); if (h.length > 60) conversationHistory.set(roomId, h.slice(-30)); }
 
 // 待处理操作
 const pendingActions = new Map();