It all feels like temporary workflow fixes until The Agent Companies just ship their opinionated good enough way to do it.

It probably is. Some of this stuff will hang around because power users want control. Some of it will evolve into more sophisticated solutions that get turned into products and become easier to acquihire than the build in house. A lot of it will become obsolete when the OEMs crib the concept. But IMO all of those are acceptable outcomes if what you really want is the thing itself.

They've already suggested using Dev Containers. https://code.claude.com/docs/en/devcontainer