feat(Localization, User Management): add missingUserId translations and enhance user ID handling

- Added translations for the "missingUserId" key in multiple languages to improve user feedback when user ID is not available.
- Updated the user ID handling in the store and WorkerSchedulesView component to ensure proper user identification when sending data to the daemon.
- Enhanced error handling to notify users when the user ID is missing, improving overall user experience.

frontend/src/i18n/locales/de/admin.json

@@ -333,6 +333,7 @@
                 "generatedAt": "Erzeugt am",
                 "empty": "Keine Schedules vorhanden.",
                 "notConnected": "Keine Daemon-Verbindung verfügbar.",
+                "missingUserId": "Keine Benutzer-ID verfügbar (setUserId fehlt).",
                 "sendError": "Anfrage an den Daemon fehlgeschlagen.",
                 "responseError": "Antwort konnte nicht verarbeitet werden.",
                 "currentStep": "Aktueller Schritt",