feat: 添加走棋记录、对局记录实体，房间新增观战开关

src/main/java/com/webgame/webgamebackend/service/GomokuGameService.java

@@ -0,0 +1,48 @@
+package com.webgame.webgamebackend.service;
+
+import com.webgame.webgamebackend.ws.RoomSessionManager;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+/**
+ * 五子棋游戏服务
+ *
+ * 处理五子棋对局的核心逻辑：落子、胜负判定、认输、和棋、准备等。
+ * TODO: 后续任务完善实现
+ */
+@Slf4j
+@Service
+public class GomokuGameService {
+
+    public void placeStone(String roomId, String userId, int row, int col, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] placeStone 暂未实现, roomId={}, userId={}, row={}, col={}", roomId, userId, row, col);
+    }
+
+    public void toggleReady(String roomId, String userId, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] toggleReady 暂未实现, roomId={}, userId={}", roomId, userId);
+    }
+
+    public void resign(String roomId, String userId, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] resign 暂未实现, roomId={}, userId={}", roomId, userId);
+    }
+
+    public void requestDraw(String roomId, String userId, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] requestDraw 暂未实现, roomId={}, userId={}", roomId, userId);
+    }
+
+    public void respondToDraw(String roomId, String userId, boolean accept, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] respondToDraw 暂未实现, roomId={}, userId={}, accept={}", roomId, userId, accept);
+    }
+
+    public void leaveRoom(String roomId, String userId, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] leaveRoom 暂未实现, roomId={}, userId={}", roomId, userId);
+    }
+
+    public void startGame(String roomId, String userId, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] startGame 暂未实现, roomId={}, userId={}", roomId, userId);
+    }
+
+    public void handleDisconnect(String roomId, String userId, RoomSessionManager sessionManager) {
+        log.warn("[GomokuGameService] handleDisconnect 暂未实现, roomId={}, userId={}", roomId, userId);
+    }
+}