Sentinel 流控算法：预热启动 构造方法中的warningToken是根据什么公式推算的，为何会直接除以coldFactor -1

## Issue Description

Type: *bug report* or *feature request*

### Describe what happened (or what feature you want)
Sentinel 中预热启动 构造方法中的warningToken是根据什么公式推算的，为何会直接除以coldFactor -1

### Describe what you expected to happen

Sentinel 中预热启动 构造方法中的warningToken是根据什么公式推算的，为何会直接除以coldFactor -1
### How to reproduce it (as minimally and precisely as possible)

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### Tell us your environment

### Anything else we need to know?

Locate the warm-up constructor and inspect how warningToken is calculated from coldFactor. Compare that calculation with the surrounding flow-control algorithm and any related tests or documentation; done should explain the formula and identify whether the implementation matches the intended behavior.

Written by the indexing model from the issue text.