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

frontend/features/billing-feature/build.gradle.kts

@@ -1,3 +1,7 @@
+@file:OptIn(ExperimentalWasmDsl::class)
+
+import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
+
 /**
  * Dieses Modul kapselt die Gebühren-Logik und Abrechnungs-Features (Billing-Sync).
  */
@@ -13,11 +17,24 @@ version = "1.0.0"
 
 kotlin {
   jvm()
-  @OptIn(org.jetbrains.kotlin.gradle.ExperimentalWasmDsl::class)
-  wasmJs {
-    browser()
+
+  js(IR) {
+    binaries.library()
+    browser {
+      testTask {
+        enabled = false
+      }
+    }
   }
 
+  wasmJs {
+    binaries.library()
+    browser {
+      testTask {
+        enabled = false
+      }
+    }
+  }
   sourceSets {
     commonMain.dependencies {
       implementation(projects.frontend.core.designSystem)

frontend/features/billing-feature/src/commonMain/kotlin/at/mocode/frontend/features/billing/data/DefaultBillingRepository.kt

@@ -42,4 +42,8 @@ class DefaultBillingRepository(
     override suspend fun getRechnungPdf(kontoId: String): Result<ByteArray> = runCatching {
         client.get(ApiRoutes.Billing.rechnung(kontoId)).body()
     }
+
+    override suspend fun getOffenePosten(veranstaltungId: String): Result<List<TeilnehmerKontoDto>> = runCatching {
+        client.get(ApiRoutes.Billing.offenePosten(veranstaltungId)).body()
+    }
 }

frontend/features/billing-feature/src/commonMain/kotlin/at/mocode/frontend/features/billing/data/FakeBillingRepository.kt

@@ -61,4 +61,8 @@ class FakeBillingRepository : BillingRepository {
     override suspend fun getRechnungPdf(kontoId: String): Result<ByteArray> {
         return Result.success("MOCK PDF CONTENT".encodeToByteArray())
     }
+
+    override suspend fun getOffenePosten(veranstaltungId: String): Result<List<TeilnehmerKontoDto>> {
+        return Result.success(konten.filter { it.saldoCent < 0 })
+    }
 }

frontend/features/billing-feature/src/commonMain/kotlin/at/mocode/frontend/features/billing/domain/BillingRepository.kt

@@ -38,4 +38,11 @@ interface BillingRepository {
     suspend fun getRechnungPdf(
         kontoId: String
     ): Result<ByteArray>
+
+    /**
+     * Holt alle Konten mit negativem Saldo für eine Veranstaltung.
+     */
+    suspend fun getOffenePosten(
+        veranstaltungId: String
+    ): Result<List<TeilnehmerKontoDto>>
 }

frontend/features/billing-feature/src/commonMain/kotlin/at/mocode/frontend/features/billing/presentation/BillingScreen.kt

@@ -37,7 +37,34 @@ fun BillingScreen(
       Spacer(Modifier.width(8.dp))
       Text("Teilnehmer-Abrechnung", style = MaterialTheme.typography.headlineSmall)
       Spacer(Modifier.weight(1f))
-      IconButton(onClick = { viewModel.loadKonten(veranstaltungId.toString()) }) {
+
+      FilterChip(
+        selected = !state.isOffenePostenMode,
+        onClick = { viewModel.loadKonten(veranstaltungId.toString()) },
+        label = { Text("Alle") },
+        leadingIcon = if (!state.isOffenePostenMode) {
+          { Icon(Icons.Default.People, contentDescription = null, modifier = Modifier.size(18.dp)) }
+        } else null
+      )
+      Spacer(Modifier.width(8.dp))
+      FilterChip(
+        selected = state.isOffenePostenMode,
+        onClick = { viewModel.loadOffenePosten(veranstaltungId.toString()) },
+        label = { Text("Offen") },
+        leadingIcon = if (state.isOffenePostenMode) {
+          { Icon(Icons.Default.Warning, contentDescription = null, modifier = Modifier.size(18.dp), tint = MaterialTheme.colorScheme.error) }
+        } else null,
+        colors = FilterChipDefaults.filterChipColors(
+          selectedContainerColor = MaterialTheme.colorScheme.errorContainer,
+          selectedLabelColor = MaterialTheme.colorScheme.error
+        )
+      )
+
+      Spacer(Modifier.width(16.dp))
+      IconButton(onClick = {
+        if (state.isOffenePostenMode) viewModel.loadOffenePosten(veranstaltungId.toString())
+        else viewModel.loadKonten(veranstaltungId.toString())
+      }) {
         Icon(Icons.Default.Refresh, contentDescription = "Aktualisieren")
       }
     }
@@ -51,15 +78,22 @@ fun BillingScreen(
         elevation = CardDefaults.cardElevation(defaultElevation = 2.dp)
       ) {
         Column(modifier = Modifier.padding(8.dp)) {
-          Text("Teilnehmer", fontWeight = FontWeight.Bold, fontSize = 14.sp)
+          Text(
+            if (state.isOffenePostenMode) "Offene Posten" else "Teilnehmer",
+            fontWeight = FontWeight.Bold,
+            fontSize = 14.sp,
+            color = if (state.isOffenePostenMode) MaterialTheme.colorScheme.error else Color.Unspecified
+          )
           HorizontalDivider(Modifier.padding(vertical = 4.dp))
 
-          if (state.isLoading && state.konten.isEmpty()) {
+          if (state.isLoading && (state.konten.isEmpty() && state.offenePosten.isEmpty())) {
             CircularProgressIndicator(modifier = Modifier.align(Alignment.CenterHorizontally).padding(16.dp))
           }
 
+          val displayList = if (state.isOffenePostenMode) state.offenePosten else state.konten
+
           LazyColumn {
-            items(state.konten) { konto ->
+            items(displayList) { konto ->
               KontoItem(
                 konto = konto,
                 isSelected = state.selectedKonto?.id == konto.id,

frontend/features/billing-feature/src/commonMain/kotlin/at/mocode/frontend/features/billing/presentation/BillingViewModel.kt

@@ -16,6 +16,8 @@ data class BillingUiState(
   val konten: List<TeilnehmerKontoDto> = emptyList(),
   val selectedKonto: TeilnehmerKontoDto? = null,
   val buchungen: List<BuchungDto> = emptyList(),
+  val offenePosten: List<TeilnehmerKontoDto> = emptyList(),
+  val isOffenePostenMode: Boolean = false,
   val pdfData: ByteArray? = null,
   val error: String? = null
 )
@@ -29,7 +31,7 @@ class BillingViewModel(
 
   fun loadKonten(veranstaltungId: String) {
     viewModelScope.launch {
-      _uiState.value = _uiState.value.copy(isLoading = true, error = null)
+      _uiState.value = _uiState.value.copy(isLoading = true, error = null, isOffenePostenMode = false)
       try {
         repository.getKonten(veranstaltungId)
           .onSuccess { konten ->
@@ -50,6 +52,22 @@ class BillingViewModel(
     }
   }
 
+  fun loadOffenePosten(veranstaltungId: String) {
+    viewModelScope.launch {
+      _uiState.value = _uiState.value.copy(isLoading = true, error = null, isOffenePostenMode = true)
+      repository.getOffenePosten(veranstaltungId)
+        .onSuccess { konten ->
+          _uiState.value = _uiState.value.copy(offenePosten = konten, isLoading = false, error = null)
+        }
+        .onFailure {
+          _uiState.value = _uiState.value.copy(
+            isLoading = false,
+            error = "Fehler beim Laden der offenen Posten: ${it.message ?: "Unbekannter Fehler"}"
+          )
+        }
+    }
+  }
+
   fun loadKonto(veranstaltungId: String, personId: String, personName: String) {
     viewModelScope.launch {
       _uiState.value = _uiState.value.copy(isLoading = true, error = null)