Fix DHCP client unable to get IP and config not persisting

- Fixed verifyAssignment being too strict for new clients
- Fixed parseRequestedIP string conversion bug
- Fixed response sent to 0.0.0.0 instead of broadcast address
- Added SO_BROADCAST support for UDP socket
- Fixed session persistence after page refresh (localStorage)
- Added in-memory session store for auth middleware
- Added config reloader so DHCP server picks up web UI changes dynamically

uninstall.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# ========================================
+# DHCP & DNS 管理器 - Linux 卸载脚本
+# ========================================
+
+set -e
+
+INSTALL_DIR="/opt/dhcp-dns-manager"
+SERVICE_NAME="dhcp-dns-manager"
+
+echo "⚠️  警告：这将卸载 DHCP & DNS 管理器"
+echo ""
+read -p "是否继续？(y/N): " confirm
+
+if [ "$confirm" != "y" ] && [ "$confirm" != "Y" ]; then
+    echo "已取消"
+    exit 0
+fi
+
+# 停止服务
+echo "🛑 停止服务..."
+systemctl stop $SERVICE_NAME || true
+systemctl disable $SERVICE_NAME || true
+
+# 删除 systemd 服务
+echo "🗑️  删除 systemd 服务..."
+rm -f /etc/systemd/system/$SERVICE_NAME.service
+systemctl daemon-reload
+
+# 删除安装目录
+echo "🗑️  删除安装目录..."
+rm -rf $INSTALL_DIR
+
+# 删除防火墙规则
+echo "🔥 清理防火墙规则..."
+if command -v ufw &> /dev/null; then
+    ufw delete allow 53/udp || true
+    ufw delete allow 67/udp || true
+    ufw delete allow 8080/tcp || true
+elif command -v firewall-cmd &> /dev/null; then
+    firewall-cmd --permanent --remove-port=53/udp || true
+    firewall-cmd --permanent --remove-port=67/udp || true
+    firewall-cmd --permanent --remove-port=8080/tcp || true
+    firewall-cmd --reload || true
+fi
+
+echo ""
+echo "✅ 卸载完成！"
+echo ""
+echo "注意：数据库文件已删除，如需保留请提前备份："
+echo "  $INSTALL_DIR/data/dhcp-dns.db"
+echo ""