fix(security): set default AP password for setup mode

Device no longer boots as open WiFi hotspot. Default AP password
set to "zacus-setup-42" (overridable via APP_WIFI.json config).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui_freenove_allinone/include/runtime/runtime_config_types.h

@@ -13,7 +13,7 @@ struct RuntimeNetworkConfig {
   char local_ssid[33] = {0};
   char local_password[65] = {0};
   char ap_default_ssid[33] = "Freenove-Setup";
-  char ap_default_password[65] = {0};
+  char ap_default_password[65] = "zacus-setup-42";
   bool force_ap_if_not_local = false;
   bool pause_local_retry_when_ap_client = false;
   uint32_t local_retry_ms = kDefaultLocalRetryMs;