feat(alarmas): simplify alarm cards and add vacation summary row

Restyle the Alarmas root per the functional redesign: alarm cards drop
the always-visible edit/skip/delete button row for a minimal giant
time + station + switch layout. Tap opens the editor, swipe deletes
(with an AlertDialog confirmation), and the hero banner gains an
inline "Saltar" pill for the featured (soonest-firing) alarm's skip
action. No capability from the old button row is lost, only the
trigger location moved; estado_alarmas.dart and its scheduling/
snooze/dismiss-guard tests are untouched.

The vacation inline panel becomes a tappable summary row (range count
+ next-range countdown, computed over the existing estado.vacaciones)
that pushes a Vacaciones manager screen. That destination is a
placeholder for now (_PantallaVacacionesTemporal, holding the old
panel's body verbatim so add/delete-range capability is preserved) --
WU9 replaces it with the real PantallaVacaciones per design ADR-6.

New ARB keys (en/es only; other 11 locales are WU18's job):
alarmHeroSkipAction, alarmDeleteConfirmTitle/Message,
vacationRangesCount, vacationSummary{Active,Upcoming}Countdown.

lib/l10n/gen/app_localizations.dart

@@ -1570,6 +1570,24 @@ abstract class AppLocalizations {
   /// **'Eliminar'**
   String get deleteTooltip;
 
+  /// No description provided for @alarmHeroSkipAction.
+  ///
+  /// In es, this message translates to:
+  /// **'Saltar'**
+  String get alarmHeroSkipAction;
+
+  /// No description provided for @alarmDeleteConfirmTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'¿Eliminar alarma?'**
+  String get alarmDeleteConfirmTitle;
+
+  /// No description provided for @alarmDeleteConfirmMessage.
+  ///
+  /// In es, this message translates to:
+  /// **'Esta acción no se puede deshacer.'**
+  String get alarmDeleteConfirmMessage;
+
   /// No description provided for @alarmSkippedNoNextSnackbar.
   ///
   /// In es, this message translates to:
@@ -1838,6 +1856,24 @@ abstract class AppLocalizations {
   /// **'Eliminar rango'**
   String get deleteRangeTooltip;
 
+  /// No description provided for @vacationRangesCount.
+  ///
+  /// In es, this message translates to:
+  /// **'{count} rangos'**
+  String vacationRangesCount(int count);
+
+  /// No description provided for @vacationSummaryActiveCountdown.
+  ///
+  /// In es, this message translates to:
+  /// **'En curso · quedan {days} días'**
+  String vacationSummaryActiveCountdown(int days);
+
+  /// No description provided for @vacationSummaryUpcomingCountdown.
+  ///
+  /// In es, this message translates to:
+  /// **'Próximo rango en {days} días'**
+  String vacationSummaryUpcomingCountdown(int days);
+
   /// No description provided for @vacationsDefaultName.
   ///
   /// In es, this message translates to: