feat: add Makefile and systemd service for linux deployment

Makefile

@@ -0,0 +1,48 @@
+BINARY_NAME=env-guard-server
+SERVICE_NAME=env-guard.service
+INSTALL_DIR=/usr/local/bin
+SYSTEMD_DIR=/etc/systemd/system
+WORK_DIR=/var/lib/env-guard
+
+.PHONY: all build build-linux clean install uninstall
+
+all: build
+
+build:
+	go build -o $(BINARY_NAME) ./cmd/server
+
+# Cross-compilation for Linux (useful if running this on Windows/Mac)
+build-linux:
+	GOOS=linux GOARCH=amd64 go build -o $(BINARY_NAME) ./cmd/server
+
+clean:
+	rm -f $(BINARY_NAME)
+
+install: build-linux
+	@echo "Installing server..."
+	mkdir -p $(INSTALL_DIR)
+	cp $(BINARY_NAME) $(INSTALL_DIR)/
+	chmod +x $(INSTALL_DIR)/$(BINARY_NAME)
+	
+	@echo "Creating working directory..."
+	mkdir -p $(WORK_DIR)
+	# Copy initial data files if they exist locally and not on target, 
+	# otherwise app will create default/empty ones based on its logic.
+	# if [ -f services.json ]; then cp -n services.json $(WORK_DIR)/; fi
+	# if [ -f history.json ]; then cp -n history.json $(WORK_DIR)/; fi
+	
+	@echo "Installing systemd service..."
+	cp $(SERVICE_NAME) $(SYSTEMD_DIR)/
+	systemctl daemon-reload
+	systemctl enable $(SERVICE_NAME)
+	systemctl start $(SERVICE_NAME)
+	@echo "Service installed and started!"
+
+uninstall:
+	@echo "Uninstalling..."
+	systemctl stop $(SERVICE_NAME) || true
+	systemctl disable $(SERVICE_NAME) || true
+	rm -f $(SYSTEMD_DIR)/$(SERVICE_NAME)
+	rm -f $(INSTALL_DIR)/$(BINARY_NAME)
+	systemctl daemon-reload
+	@echo "Uninstalled."