server VS golangci-lint

You still end up with the same problem, though, just in a container instead of directly on your computer's filesystem. The root issue is that if you are working on two modules where one depends on the other, say github.com/yourname/server and github.com/yourname/client, the compiler (and gopls) is checking your function calls, etc. against the version in the repository, not the version you have on your computer that you just modified. This means that you would have to make a change, commit it to the repo, then do go mod download to get the changes, and then check to see if they work.

Hey, I try to figure out an elegant way to integrate golangci into a Go project.

All of this is nitpicking really, but I would suggest using linters, e.g. https://github.com/golangci/golangci-lint - sometimes annoying, but mostly just helps to avoid discussions like this (and plethora of bugs).

You should always use golangci-lint, which includes errcheck.

golangci lint - https://golangci-lint.run/

Code inspection golangci-lint

I disagree with at least half of your post, tooling in Go is amazing overall and there is one linter that pretty much every one is using: https://github.com/golangci/golangci-lint

There is a single linter that many people use. It rolls other linters into one. FWIW, it's here: https://github.com/golangci/golangci-lint.