fix(alarmas): show which days a weekday alarm actually fires on

The alarms list showed a generic "Días" label for a diasSemana alarm
instead of its actual configured days. Render the real recurrence (e.g.
"Lun, Mié, Vie") by reusing the SAME per-day abbreviation the editor's own
day-picker circles already use -- no new formatting scheme, no new ARB
keys for the days themselves.

Also surface fade/volume/vacation-pause state on the card, each only when
it is a genuinely useful deviation from the common case: a fade badge when
fadeInSegundos > 0 (reusing the existing alarmFadeInLabel key), a volume
percentage when it differs from the 85% default, and a vacation-paused
badge when the alarm is both configured to pause and a vacation range is
currently active (mirrors the exact predicate ServicioProgramacionAlarmas
already uses). One compact line, not a badge per field.

Fixes a text-collision regression in pantalla_alarmas_editor_test.dart:
opening the editor for an alarm whose own day now renders on its card
(e.g. "Lun") made a bare find.text(weekday) ambiguous against the editor's
day-picker circle with the same label -- scoped that finder to the
BottomSheet subtree.

lib/l10n/app_de.arb

@@ -840,5 +840,6 @@
         "type": "String"
       }
     }
-  }
+  },
+  "alarmCardVacationPausedBadge": "Wegen Urlaub pausiert"
 }