chore: remove unused meldestelle-portal module

- Deleted obsolete `meldestelle-portal` module, including all associated screens, configurations, tests, and assets.
- Includes removal of Compose multiplatform dependencies in `build.gradle.kts`.
- Cleaned up redundant files such as `AppPreview`, `AuthStatusScreen`, `DashboardScreen`, and associated core implementations.
- Streamlined module references in `settings.gradle.kts`.

Signed-off-by: Stefan Mogeritsch <stefan.mo.co@gmail.com>

frontend/features/zns-import-feature/build.gradle.kts

@@ -0,0 +1,28 @@
+/**
+ * Feature-Modul: ZNS-Stammdaten-Import (Desktop-only)
+ * Kapselt ViewModel, State und API-Kommunikation für den ZNS-Import.
+ */
+plugins {
+  alias(libs.plugins.kotlinMultiplatform)
+  alias(libs.plugins.composeCompiler)
+}
+group = "at.mocode.clients"
+version = "1.0.0"
+
+kotlin {
+  jvm()
+  sourceSets {
+    jvmMain.dependencies {
+      implementation(projects.frontend.core.network)
+      implementation(projects.frontend.core.auth)
+      implementation(libs.bundles.kmp.common)
+      implementation(libs.koin.core)
+      implementation(libs.ktor.client.core)
+      implementation(libs.ktor.client.contentNegotiation)
+      implementation(libs.ktor.client.serialization.kotlinx.json)
+      implementation(libs.androidx.lifecycle.viewmodelCompose)
+      implementation(libs.kotlinx.coroutines.core)
+      implementation(libs.kotlinx.serialization.json)
+    }
+  }
+}

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

@@ -0,0 +1,140 @@
+package at.mocode.zns.feature
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import at.mocode.frontend.core.auth.data.AuthTokenManager
+import at.mocode.frontend.core.network.NetworkConfig
+import io.ktor.client.*
+import io.ktor.client.request.*
+import io.ktor.client.request.forms.*
+import io.ktor.client.statement.*
+import io.ktor.http.*
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.Json
+import java.io.File
+
+data class ZnsImportState(
+  val selectedFilePath: String? = null,
+  val isUploading: Boolean = false,
+  val jobId: String? = null,
+  val jobStatus: String? = null,
+  val progress: Int = 0,
+  val progressDetail: String = "",
+  val errors: List<String> = emptyList(),
+  val errorMessage: String? = null,
+  val isFinished: Boolean = false,
+)
+
+@Serializable
+internal data class JobIdResponse(val jobId: String)
+
+@Serializable
+internal data class JobStatusResponse(
+  val jobId: String,
+  val status: String,
+  val progress: Int = 0,
+  val progressDetail: String = "",
+  val errors: List<String> = emptyList(),
+)
+
+private val TERMINAL_STATES = setOf("ABGESCHLOSSEN", "FEHLER")
+private const val POLLING_INTERVAL_MS = 2000L
+private const val MAX_VISIBLE_ERRORS = 50
+
+class ZnsImportViewModel(
+  private val httpClient: HttpClient,
+  private val authTokenManager: AuthTokenManager,
+) : ViewModel() {
+
+  var state by mutableStateOf(ZnsImportState())
+    private set
+
+  private var pollingJob: Job? = null
+  private val json = Json { ignoreUnknownKeys = true }
+
+  fun onFileSelected(path: String) {
+    state = ZnsImportState(selectedFilePath = path)
+  }
+
+  fun startImport() {
+    val filePath = state.selectedFilePath ?: return
+    val file = File(filePath)
+    if (!file.exists() || !file.name.endsWith(".zip", ignoreCase = true)) {
+      state = state.copy(errorMessage = "Bitte eine gültige .zip-Datei auswählen.")
+      return
+    }
+
+    viewModelScope.launch {
+      state = state.copy(
+        isUploading = true, errorMessage = null, isFinished = false,
+        jobId = null, progress = 0, progressDetail = "", errors = emptyList()
+      )
+      try {
+        val token = authTokenManager.authState.value.token
+        val response: HttpResponse = httpClient.post("${NetworkConfig.baseUrl}/api/v1/import/zns") {
+          if (token != null) header(HttpHeaders.Authorization, "Bearer $token")
+          setBody(MultiPartFormDataContent(formData {
+            append("file", file.readBytes(), Headers.build {
+              append(HttpHeaders.ContentDisposition, "filename=\"${file.name}\"")
+              append(HttpHeaders.ContentType, "application/zip")
+            })
+          }))
+        }
+        if (response.status == HttpStatusCode.Accepted) {
+          val body = json.decodeFromString<JobIdResponse>(response.bodyAsText())
+          state = state.copy(isUploading = false, jobId = body.jobId, jobStatus = "AUSSTEHEND")
+          startPolling(body.jobId)
+        } else {
+          state = state.copy(isUploading = false, errorMessage = "Upload fehlgeschlagen: HTTP ${response.status.value}")
+        }
+      } catch (e: Exception) {
+        state = state.copy(isUploading = false, errorMessage = "Fehler beim Upload: ${e.message}")
+      }
+    }
+  }
+
+  private fun startPolling(jobId: String) {
+    pollingJob?.cancel()
+    pollingJob = viewModelScope.launch {
+      while (true) {
+        try {
+          val token = authTokenManager.authState.value.token
+          val response: HttpResponse = httpClient.get("${NetworkConfig.baseUrl}/api/v1/import/zns/$jobId/status") {
+            if (token != null) header(HttpHeaders.Authorization, "Bearer $token")
+          }
+          if (response.status.isSuccess()) {
+            val status = json.decodeFromString<JobStatusResponse>(response.bodyAsText())
+            state = state.copy(
+              jobStatus = status.status,
+              progress = status.progress,
+              progressDetail = status.progressDetail,
+              errors = status.errors.takeLast(MAX_VISIBLE_ERRORS),
+              isFinished = status.status in TERMINAL_STATES,
+            )
+            if (status.status in TERMINAL_STATES) break
+          }
+        } catch (e: Exception) {
+          state = state.copy(errorMessage = "Polling-Fehler: ${e.message}", isFinished = true)
+          break
+        }
+        delay(POLLING_INTERVAL_MS)
+      }
+    }
+  }
+
+  fun reset() {
+    pollingJob?.cancel()
+    state = ZnsImportState()
+  }
+
+  override fun onCleared() {
+    super.onCleared()
+    pollingJob?.cancel()
+  }
+}

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

@@ -0,0 +1,9 @@
+package at.mocode.zns.feature.di
+
+import at.mocode.zns.feature.ZnsImportViewModel
+import org.koin.core.qualifier.named
+import org.koin.dsl.module
+
+val znsImportModule = module {
+  factory { ZnsImportViewModel(get(named("apiClient")), get()) }
+}