Linters

We need linters to check some basic stuff. To start off, we can use `golangci-lint`. We might have to use some custom built linters too, or other third party linters to get some of the below features

- We should almost always use our `log` package and not the standard library `log` package
- We should never use "/" as file path separator in our code and instead use `filepath.Join()` always from the `filepath` standard library

Start by reviewing the repository's Go code and deciding how golangci-lint should be configured. Check how the custom rules would identify use of the standard-library log package and slash path separators instead of filepath.Join(). Done means the requested lint checks run consistently and flag the stated patterns.

Written by the indexing model from the issue text.