fix: Beheben des Deserialisierungsfehlers beim Web-App-Import

- Ändert die Datentypen für `is_standard` und `marked` in der `Item`-Datenklasse von `Boolean` auf `Int`, um sie an die API-Antwort (0/1) anzupassen.
- Verbessert die Importlogik, um das Hinzufügen doppelter Artikel zu verhindern.

app/src/main/java/de/lxtools/noteshop/api/WebAppClient.kt

@@ -28,9 +28,9 @@ data class TokenResponse(
 data class Item(
     val id: Int,
     val name: String,
-    val is_standard: Boolean,
+    val is_standard: Int,
     val created_by_user_id: Int?,
-    val marked: Boolean
+    val marked: Int
 )
 
 @Serializable
@@ -55,6 +55,7 @@ class WebAppClient {
             json(Json {
                 ignoreUnknownKeys = true
                 prettyPrint = true
+                isLenient = true
             })
         }
         expectSuccess = false // Don't throw exceptions for non-2xx responses

app/src/main/java/de/lxtools/noteshop/data/NoteshopRepository.kt

@@ -2,6 +2,7 @@ package de.lxtools.noteshop.data
 
 import de.lxtools.noteshop.api.WebAppClient
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.firstOrNull
 
 /**
  * Repository that provides insert, update, delete, and retrieve of data from a given data source.
@@ -256,10 +257,18 @@ class OfflineNoteshopRepository(
 
     override suspend fun importItemsFromWebApp(listId: Int, url: String, user: String, pass: String) {
         val itemsFromWeb = webAppClient.fetchItems(url, user, pass)
-        val newItems = itemsFromWeb.map { itemName ->
+        // Get existing items to prevent duplicates
+        val existingItemNames = getShoppingListWithItemsStream(listId).firstOrNull()?.items?.map { it.name.lowercase() } ?: emptyList()
+        val newItems = itemsFromWeb.filter { itemName ->
+            itemName.lowercase() !in existingItemNames
+        }.map { itemName ->
             ShoppingListItem(listId = listId, name = itemName)
         }
-        insertShoppingListItems(newItems)
+
+        if (newItems.isNotEmpty()) {
+            insertShoppingListItems(newItems)
+        }
+        // Always mark all fetched items as processed on the server
         webAppClient.markItems(url, user, pass, itemsFromWeb)
     }