build: 添加 Makefile 用于构建管理

添加 Makefile 文件，包含构建、清理、测试和多平台构建功能，简化开发流程

Makefile

@@ -0,0 +1,28 @@
+.PHONY: clean test build build-all
+
+# 构建目标
+BINARY := gofirewall
+
+# 默认构建
+build:
+	@echo "Building for current platform..."
+	go build -o $(BINARY)
+
+# 清理构建产物
+clean:
+	@echo "Cleaning build artifacts..."
+	@rm -f $(BINARY) $(BINARY)-*
+
+# 运行测试
+test:
+	@echo "Running tests..."
+	go test ./...
+
+# 多平台构建
+build-all: clean test
+	@echo "Building for all platforms..."
+	GOOS=linux GOARCH=amd64 go build -o $(BINARY)-linux-amd64
+	GOOS=linux GOARCH=arm64 go build -o $(BINARY)-linux-arm64
+	GOOS=windows GOARCH=amd64 go build -o $(BINARY)-windows-amd64.exe
+	GOOS=darwin GOARCH=amd64 go build -o $(BINARY)-darwin-amd64
+	GOOS=darwin GOARCH=arm64 go build -o $(BINARY)-darwin-arm64