chore(install): Add banner display and update confirmation

- Add show_banner() function to display XingRin ASCII art logo
- Call show_banner() before header in install.sh initialization
- Add experimental feature warning in update.sh with user confirmation
- Prompt user to confirm before proceeding with update operation
- Suggest full reinstall via uninstall.sh and install.sh as alternative
- Improve user experience with visual feedback and safety checks

install.sh

@@ -64,6 +64,22 @@ header() {
     echo -e "${BOLD}${BLUE}============================================================${RESET}"
 }
 
+# ==============================================================================
+# 显示横幅
+# ==============================================================================
+show_banner() {
+    echo -e "${CYAN}"
+    cat << 'EOF'
+    __  __ _             ____  _       
+    \ \/ /(_)_ __   __ _|  _ \(_)_ __  
+     \  / | | '_ \ / _` | |_) | | '_ \ 
+     /  \ | | | | | (_| |  _ <| | | | |
+    /_/\_\|_|_| |_|\__, |_| \_\_|_| |_|
+                   |___/                
+EOF
+    echo -e "${RESET}"
+}
+
 # ==============================================================================
 # 权限检查
 # ==============================================================================
@@ -96,6 +112,7 @@ else
 fi
 
 # 显示标题
+show_banner
 header "XingRin 一键安装脚本 (Ubuntu)"
 info "当前用户: ${BOLD}$REAL_USER${RESET}"
 info "项目路径: ${BOLD}$ROOT_DIR${RESET}"

update.sh

@@ -83,6 +83,20 @@ fi
 echo -e "${BOLD}${BLUE}╚════════════════════════════════════════╝${NC}"
 echo ""
 
+# 测试性功能警告
+echo -e "${BOLD}${YELLOW}[!] 警告：此功能为测试性功能，可能会导致升级失败${NC}"
+echo -e "${YELLOW}    建议运行 ./uninstall.sh 后重新执行 ./install.sh 进行全新安装${NC}"
+echo ""
+echo -n -e "${YELLOW}是否继续更新？(y/N) ${NC}"
+read -r ans_continue
+ans_continue=${ans_continue:-N}
+
+if [[ ! $ans_continue =~ ^[Yy]$ ]]; then
+    echo -e "${CYAN}已取消更新。${NC}"
+    exit 0
+fi
+echo ""
+
 echo -e "${CYAN}[1/4]${NC} 停止服务..."
 ./stop.sh 2>&1 | sed 's/^/    /'