Add Makefile and helper commands (#3)

* Add makefile build helpers, including version bump

* Fix fmt issue in version bump make target

Author: dannykansas

Makefile

@@ -0,0 +1,104 @@
+# rightsizer Makefile
+
+# Variables
+BINARY_NAME := rightsizer
+DOCKER_IMAGE := nextroll/rightsizer
+GO_FILES := $(shell find . -name '*.go' -type f)
+
+# Default target
+.PHONY: all
+all: build
+
+# Build the binary
+.PHONY: build
+build:
+	go build -o $(BINARY_NAME) .
+
+# Generate mocks
+.PHONY: generate
+generate:
+	go generate ./...
+
+# Run tests
+.PHONY: test
+test: generate
+	go test ./...
+
+# Clean build artifacts
+.PHONY: clean
+clean:
+	rm -f $(BINARY_NAME)
+
+# Build Docker image
+.PHONY: docker-build
+docker-build:
+	docker build -t $(DOCKER_IMAGE) .
+
+# Run with Docker
+.PHONY: docker-run
+docker-run:
+	docker run --rm $(DOCKER_IMAGE) $(BINARY_NAME) $(ARGS)
+
+# Install dependencies
+.PHONY: deps
+deps:
+	go mod download
+	go mod tidy
+
+# Format code
+.PHONY: fmt
+fmt:
+	go fmt ./...
+
+# Vet code
+.PHONY: vet
+vet:
+	go vet ./...
+
+# Run linter (requires golangci-lint)
+.PHONY: lint
+lint:
+	golangci-lint run
+
+# Full check: format, vet, generate, test
+.PHONY: check
+check: fmt vet generate test
+
+# Bump version
+.PHONY: version-bump
+version-bump:
+	@if [ -z "$(VERSION)" ]; then \
+		echo "Usage: make version-bump VERSION=x.y.z"; \
+		exit 1; \
+	fi
+	@echo "Bumping version to $(VERSION)..."
+	@sed -i '' 's/Version:.*"[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*"/Version: "$(VERSION)"/' main.go
+	@echo "Version updated to $(VERSION) in main.go"
+	@# Extract major and minor versions for workflow tags
+	@MAJOR=$$(echo $(VERSION) | cut -d. -f1); \
+	MINOR=$$(echo $(VERSION) | cut -d. -f2); \
+	sed -i '' "s/nextroll\/rightsizer:v[0-9][0-9]*/nextroll\/rightsizer:v$$MAJOR/" .github/workflows/ship-version.yml; \
+	sed -i '' "s/nextroll\/rightsizer:v[0-9][0-9]*\.[0-9][0-9]*/nextroll\/rightsizer:v$$MAJOR.$$MINOR/" .github/workflows/ship-version.yml; \
+	sed -i '' "s/nextroll\/rightsizer:v[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*/nextroll\/rightsizer:v$(VERSION)/" .github/workflows/ship-version.yml
+	@echo "Running go fmt..."
+	go fmt ./...
+	@echo "Version updated to $(VERSION) in .github/workflows/ship-version.yml"
+	
+
+# Help
+.PHONY: help
+help:
+	@echo "Available targets:"
+	@echo "  build        - Build the rightsizer binary"
+	@echo "  generate     - Generate mocks using go generate"
+	@echo "  test         - Run tests (generates mocks first)"
+	@echo "  clean        - Remove build artifacts"
+	@echo "  docker-build - Build Docker image"
+	@echo "  docker-run   - Run with Docker (use ARGS='cluster service')"
+	@echo "  deps         - Download and tidy Go modules"
+	@echo "  fmt          - Format Go code"
+	@echo "  vet          - Run go vet"
+	@echo "  lint         - Run golangci-lint"
+	@echo "  check        - Run fmt, vet, generate, and test"
+	@echo "  version-bump - Bump version (use VERSION=x.y.z)"
+	@echo "  help         - Show this help message"