feat: add Makefile for build, lint and testing automation and add golangci config

Signed-off-by: Marc Schäfer <git@marcschaeferger.de>

Makefile

@@ -0,0 +1,51 @@
+YAEGI_VERSION ?= v0.16.1
+GOVULNCHECK_VERSION ?= v1.3.0
+
+.PHONY: fmt tidy vet lint test vulncheck vendor yaegi-test ci ci-full clean
+
+fmt:
+	gofmt -w .
+
+tidy:
+	go mod tidy
+
+vet:
+	go vet ./...
+
+lint:
+	golangci-lint run
+
+test:
+	go test -race -cover ./...
+
+vulncheck:
+	go install golang.org/x/vuln/cmd/govulncheck@$(GOVULNCHECK_VERSION)
+	govulncheck ./...
+
+vendor:
+	go mod vendor
+
+# Yaegi compatibility check. Vendors dependencies first so Yaegi can resolve
+# local sub-packages (e.g. github.com/fosrl/badger/ips) without needing a
+# plugins-local copy layout. Must be run from a GOPATH-compatible directory
+# (go/src/github.com/fosrl/badger) for local sub-package resolution.
+yaegi-test: vendor
+	go run github.com/traefik/yaegi/cmd/yaegi@$(YAEGI_VERSION) test -v .
+
+# Reproduce the CI checks locally (excluding yaegi and lint).
+ci:
+	test -z "$$(gofmt -l .)"
+	go mod tidy
+	git diff --exit-code -- go.mod go.sum
+	go vet ./...
+	go test -race -cover ./...
+	go install golang.org/x/vuln/cmd/govulncheck@$(GOVULNCHECK_VERSION)
+	govulncheck ./...
+
+# Full CI including lint and yaegi compatibility check.
+ci-full: ci
+	$(MAKE) lint
+	$(MAKE) yaegi-test
+
+clean:
+	rm -rf vendor