[Bug]: agentStateStore does not support Redis Cluster.

**Describe the bug**

Redis Cluster 模式下，多 key 的 Lua 脚本 (EVAL) 要求所有 key 哈希到同一 slot，否则抛出 CROSSSLOT Keys in request don't hash to the same slot。

1. redis cluster
2. agentStateStore.save(userId, conversationId, "agent_state", state);
3. org.redisson.client.RedisException: CROSSSLOT Keys in request don't hash to the same slot.

**To Reproduce**
Steps to reproduce the behavior:

@Bean
public AgentStateStore agentStateStore(RedissonClient redissonClient){
return RedisAgentStateStore.builder()
.redissonClient(redissonClient)
.keyPrefix("sa:session:")
.build();
}

agentStateStore.save(userId, conversationId, "agent_state", state);

**Environment (please complete the following information):**

- AgentScope-Java Version: 2.0.1-SNAPSHOT
- Java Version: 21
- OS: windows