feat(frontend): confirm before stopping Xray and offer Start when it is stopped (#7104)

Stop sat next to Restart on the dashboard and fired on the first click. A
mis-click cut every proxy connection, and when the panel itself is reached
through that proxy the only way back was SSH (#7103).

Stop now opens a confirmation with Cancel focused. When Xray is stopped the
first button reads Start instead of Restart and Stop is disabled; in the
crashed state Stop stays enabled, because setting the manual-stop flag is
what halts the crash-recovery restart loop.

Closes #7103

internal/web/translation/pt-BR.json

@@ -151,6 +151,11 @@
       "xrayStatus": "Xray",
       "stopXray": "Parar",
       "restartXray": "Reiniciar",
+      "startXray": "Iniciar",
+      "stopXrayDisabledHint": "O Xray não está em execução",
+      "stopXrayConfirmTitle": "Parar o Xray?",
+      "stopXrayConfirmContent": "Parar o Xray interromperá imediatamente todas as conexões de proxy. Tem certeza de que deseja continuar?",
+      "stopXrayConfirmOk": "Parar o Xray",
       "xraySwitch": "Versão",
       "xrayUpdates": "Atualizações do Xray",
       "xraySwitchClickDesk": "Escolha com cuidado, pois versões mais antigas podem não ser compatíveis com as configurações atuais.",