fix: wait for NM auto-reconnect before starting AP on reboot

After WiFi is configured and device reboots, NetworkManager needs
a few seconds to auto-connect to saved WiFi. Without waiting,
AP starts immediately and occupies wlan0, preventing NM reconnect.

- Add hasSavedWifiConnection() to check for saved WiFi profiles
- Wait up to 20s for NM auto-connect before falling back to AP
- First boot (no saved WiFi) still starts AP immediately

Made-with: Cursor

lib/network.js

@@ -173,6 +173,22 @@ function sleep(ms) {
   execSync(`sleep ${ms / 1000}`, { timeout: ms + 2000 });
 }
 
+/**
+ * 检测是否有已保存的 WiFi STA 连接（排除自身热点）
+ */
+function hasSavedWifiConnection() {
+  try {
+    const out = run('nmcli -t -f NAME,TYPE connection show');
+    for (const line of out.split('\n')) {
+      const [name, type] = line.split(':');
+      if (type === '802-11-wireless' && name !== CON_NAME) {
+        return true;
+      }
+    }
+  } catch (_) {}
+  return false;
+}
+
 /**
  * 检测 wlan0 是否以 STA 模式连接了 WiFi（排除自身热点）
  */
@@ -192,6 +208,7 @@ function isWifiStaConnected() {
 
 module.exports = {
   hasInternet,
+  hasSavedWifiConnection,
   isWifiStaConnected,
   getWifiIface,
   scanWifi,