Remove domain models and services related to Abteilung, AbteilungsRegelService, and Bewerb: cleanup unnecessary entities, validation logic, and tests across backend modules.

frontend/features/zns-import-feature/src/jvmMain/kotlin/at/mocode/zns/feature/ZnsImportViewModel.kt

@@ -18,6 +18,7 @@ import kotlinx.coroutines.launch
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.Json
 import java.io.File
+import kotlin.time.Duration.Companion.milliseconds
 
 data class ZnsImportState(
   val selectedFilePath: String? = null,
@@ -123,7 +124,7 @@ class ZnsImportViewModel(
           state = state.copy(errorMessage = "Polling-Fehler: ${e.message}", isFinished = true)
           break
         }
-        delay(POLLING_INTERVAL_MS)
+        delay(POLLING_INTERVAL_MS.milliseconds)
       }
     }
   }