fix(network): wired ping probe, AP/WS and systemd notify hardening

- Add hasWiredInternetProbe and export; AP mode uses it with hasInternet
- systemd-env: strip NOTIFY_SOCKET from env early; client uses unix_dgram
- Strip NOTIFY_SOCKET from frpc/ttyd spawn env in watchdog and frpc
- WS: pong miss debounce; AP net monitor consecutive-fail debounce

Made-with: Cursor

lib/network.js

@@ -79,6 +79,20 @@ function _tryPingInternet() {
   return false;
 }
 
+/**
+ * 仅经有线口 ping 公网（不依赖默认路由）。
+ * AP 开启时 hasInternet() 易误判；维持 WS / 网络监视时用此兜底。
+ */
+function hasWiredInternetProbe() {
+  const wired = getWiredIfaceWithCarrier();
+  if (!wired) return false;
+  try {
+    run(`ping -c 1 -W 3 -I ${wired} 8.8.8.8`);
+    return true;
+  } catch (_) {}
+  return false;
+}
+
 /**
  * 检测是否有互联网连接（nmcli 连通性 + ping 兜底）
  */
@@ -298,6 +312,7 @@ function getLocalIps() {
 module.exports = {
   hasInternet,
   hasWiredCarrier,
+  hasWiredInternetProbe,
   getWiredIfaceWithCarrier,
   hasSavedWifiConnection,
   isWifiStaConnected,