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/pt-BR.json

@@ -1627,7 +1627,8 @@
         "testSuccess": "Teste bem-sucedido",
         "testFailed": "Teste falhou",
         "testError": "Falha ao testar saída",
-        "testModeTooltip": "TCP: sondagem rápida apenas de dial. HTTP: requisição completa pelo xray.",
+        "modeRealDelay": "Latência real",
+        "testModeTooltip": "TCP: sondagem rápida apenas de dial. HTTP: requisição completa pelo xray. Latência real: tempo total incluindo o estabelecimento da conexão.",
         "testAll": "Testar todos",
         "httpStatus": "Status HTTP",
         "breakdownConnect": "Conexão do proxy",