[Request]: Setup and Use GolangCI Lint for the project

### Feature or enhancement request details

I'd like to propose adding [golangci-lint](https://github.com/golangci/golangci-lint) to this project to improve code quality through consistent static analysis and linting.

### Proposal

A .golangci.yml file in the root directory with common checks enabled (happy to suggest a config). Optionally run it in CI (e.g., GitHub Actions) to ensure lint compliance on PRs.

I’d be happy to open a PR adding:
* A basic .golangci.yml config
* CI integration (if desired)

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct

Start by reviewing the Go project and its existing CI configuration, then decide which golangci-lint checks belong in a root-level .golangci.yml. Done means a basic lint configuration is added and, if CI integration is chosen, pull requests run the linter successfully.

Written by the indexing model from the issue text.