Adds a `make check` target that verifies formatting (gofmt), linting (golangci-lint), and tests (go test -race) without modifying files.
Also adds `.gitea/workflows/check.yml` CI workflow that runs on pushes and PRs to main.
`make check` passes cleanly on current main.
Co-authored-by: user <user@Mac.lan guest wan>
Co-authored-by: clawbot <clawbot@noreply.git.eeqj.de>
Co-authored-by: clawbot <clawbot@sneak.berlin>
Reviewed-on: #42
Co-authored-by: clawbot <sneak+clawbot@sneak.cloud>
Co-committed-by: clawbot <sneak+clawbot@sneak.cloud>
