"[upset|overturn] the apple cart" 的定义和意义

What is the origin of the idiom "upset the apple cart" and when to use it?

The idiom "upset the apple cart" originates from the image of a person accidentally or intentionally tipping over a cart filled with apples, creating a mess and disrupting order. It is used to describe an action that causes chaos, disruption, or ruins existing plans, often due to carelessness or a sudden change in circumstances.