Feasibility discussion of fuse/current limiting in cloud computing

## Issue Description

Type: *feature request*

### Describe what happened (or what feature you want)

Sentinel以客户端计算为主，客户端计算有几个不足：

* 上下文不完整，只能看到进程内的流量态势，看不到全局（包括nginx/db）

* 计算深度有限，没有计算引擎（Database），难以进行复杂的计算

* 难以支持有关联的多服务协同调度（熔断/限流）

* 流控逻辑以FatJar的形态存在于客户端，更新版本较为困难

* 计算逻辑无法复用，难以支持多语言（如java+go）

### Describe what you expected to happen

* 客户端接入jvm-sandbox，可利用sandbox实现热升级

* 客户端只保留 资源埋点、打点上报、执行熔断/限流 这3项基本能力

* 熔断/限流的开始与恢复由服务端统一指挥

No files, tests, or entry points are named. Start by reviewing the issue's proposed split between client responsibilities and server-directed circuit breaking/rate limiting, including the JVM-Sandbox integration, and identify the relevant Sentinel architecture before proceeding. Done would require an agreed feasibility direction and an implementation scope for coordinated multi-service control.

Written by the indexing model from the issue text.