I don't know if there is an official name, but in my head I call it "helpers/components/mixins are better than frameworks." Or, "if one happens to want to write a framework, one ought to try hard to refactor it 'inside-out' to a set of composable components."

The most important (though not only) issue with frameworks is that you typically can't compose/mix more than one together - every framework is "exclusive" and takes control of the code flow. Whereas "components" can usually be easily mixed with each other, and leave control of the code flow to the programmer.

I generally think of this as the same principle of "prefer composition over inheritence". Leave the top-level free to compose the behaviour it requires rather than inheriting the framework's behaviour, for exactly the reasons you describe.

This is frameworks vs libraries. In the first case the framework is calling the code with config and hooks to change behaviour. In the second case there are common library functions called from completely separate “application” code.

I don't know an official name for it. It seems like it's almost too basic - "subdivide into helper functions" - to make it into the Gang of Four or other design pattern collections. But in my head I'm calling it the "Recipe Pattern"

It sounds like a version of the strategy pattern to me.

https://en.wikipedia.org/wiki/Strategy_pattern