fix(net): start SNTP with the saved timezone

configTime() sets TZ to UTC, which undid the saved rule on every join.

src/net.cpp

@@ -97,8 +97,8 @@ void net::loop() {
   // Started per join rather than once at boot: a fresh lease may hand us a
   // different NTP server, and the daemon re-syncs on its own hourly from here.
   sntp_servermode_dhcp(1);
-  configTime(0, 0, "pool.ntp.org",
-             "time.nist.gov"); // UTC; the UI decides how to show it
+  // configTime() would overwrite TZ with UTC, so hand it the saved rule.
+  configTzTime(settings.timezone.c_str(), "pool.ntp.org", "time.nist.gov");
   Serial.println("[net] wifi up, sntp started");
 }