修复无法编译的错误

install.sh

@@ -91,6 +91,12 @@ build_sing_box() {
     # Reduced tags for safer build on smaller servers
     TAGS="with_quic,with_utls,with_clash_api,with_gvisor,with_acme"
 
+    echo -e "${YELLOW}Downloading Go modules and refreshing go.sum entries...${NC}"
+    if ! go mod download; then
+        echo -e "${RED}Failed to download Go modules.${NC}"
+        exit 1
+    fi
+    
     echo -e "${YELLOW}Starting compilation (this may take a few minutes)...${NC}"
     echo -e "${YELLOW}Note: Using -p 1 to save memory and avoid silent crashes.${NC}"