feat(alarmas): surface scheduling failures on the alarm card

Wires EstadoAlarmas.ultimaExcepcionPara into PantallaAlarmas: an
alarm with an outstanding scheduling-failure exception now shows a
calm warning line (distinguishing a pre-notice-only failure from the
alarm itself not being registered) with a tap target into the
reliability diagnostics screen. The warning is its own small tap
target nested inside the existing card InkWell, so tap-to-edit,
swipe-to-delete and the hero "Saltar" chip are untouched.

Adds alarmCardSchedulingFailedMessage/alarmCardPreNoticeFailedMessage
to all 13 ARB locales with real per-language translations (verified
against arb_parity_test and arb_anti_copy_test).

lib/l10n/app_es.arb

@@ -801,6 +801,8 @@
     }
   },
   "alarmCardVacationPausedBadge": "Pausada por vacaciones",
+  "alarmCardSchedulingFailedMessage": "Esta alarma no se pudo registrar en el sistema, así que podría no sonar.",
+  "alarmCardPreNoticeFailedMessage": "Esta alarma está programada, pero no se pudo activar su aviso previo.",
   "alarmDiagnosticsExactAlarmsTitle": "Programación de alarma exacta",
   "alarmDiagnosticsExactAlarmsHint": "Permite que la alarma suene en el minuto exacto que elegiste, incluso con el teléfono en reposo.",
   "alarmDiagnosticsNotificationsTitle": "Notificaciones",