feat(outbound): add real-delay connection test mode

The HTTP probe reports the warm per-request round-trip, which reads
lower than the delay figure client apps show for the same server. Add a
third "real" test mode that reuses the temp-instance HTTP probe but
reports the cold request's full elapsed time - tunnel establishment
included - and skips the warm request. UDP-transport outbounds forced
out of the TCP lane still report "http"; in real mode they report
"real". The mode joins the TCP/HTTP toggle on the outbounds tab, with
the label translated in all 13 locales.

internal/web/translation/es-ES.json

@@ -1627,7 +1627,8 @@
         "testSuccess": "Prueba exitosa",
         "testFailed": "Prueba fallida",
         "testError": "Error al probar la salida",
-        "testModeTooltip": "TCP: sonda rápida solo de dial. HTTP: petición completa a través de xray.",
+        "modeRealDelay": "Retardo real",
+        "testModeTooltip": "TCP: sonda rápida solo de dial. HTTP: petición completa a través de xray. Retardo real: tiempo total incluyendo el establecimiento de la conexión.",
         "testAll": "Probar todo",
         "httpStatus": "Estado HTTP",
         "breakdownConnect": "Conexión al proxy",