fix: Server-App WebSocket-Kompatibilität und DELETE-Route

- WebSocketManager: inventory_updated -> inventoryUpdated,
  full_sync_required -> fullSyncRequired (camelCase wie App erwartet)
- InventoryRoutes: DELETE /api/inventory/items/{id} hinzugefügt
- InventoryRepository: deleteItem(inventoryId, itemId) implementiert

server/src/main/kotlin/de/krisenvorrat/server/repository/InventoryRepository.kt

@@ -203,4 +203,13 @@ internal class InventoryRepository {
             updated > 0
         }
     }
+
+    fun deleteItem(inventoryId: String, itemId: String): Boolean {
+        return transaction {
+            val deleted = Items.deleteWhere {
+                (Items.id eq itemId) and (Items.inventoryId eq inventoryId)
+            }
+            deleted > 0
+        }
+    }
 }

server/src/main/kotlin/de/krisenvorrat/server/routes/InventoryRoutes.kt

@@ -52,6 +52,22 @@ internal fun Route.inventoryRoutes(
                 call.respond(HttpStatusCode.OK, item)
             }
         }
+
+        delete("/items/{id}") {
+            val userId = call.principal<UserPrincipal>()?.userId
+                ?: return@delete call.respond(HttpStatusCode.Unauthorized, ErrorResponse(status = 401, message = "Unauthorized"))
+            val inventoryId = repository.getEffectiveInventoryId(userId)
+            val itemId = call.parameters["id"] ?: return@delete call.respond(
+                HttpStatusCode.BadRequest, ErrorResponse(status = 400, message = "Missing item id")
+            )
+            val deleted = repository.deleteItem(inventoryId, itemId)
+            if (!deleted) {
+                call.respond(HttpStatusCode.NotFound, ErrorResponse(status = 404, message = "Item not found"))
+            } else {
+                wsManager.notifyInventoryUpdated(userId, itemId)
+                call.respond(HttpStatusCode.NoContent)
+            }
+        }
     }
 }
 

server/src/main/kotlin/de/krisenvorrat/server/websocket/WebSocketManager.kt

@@ -26,7 +26,7 @@ internal class WebSocketManager {
 
     suspend fun notifyInventoryUpdated(userId: String, itemId: String) {
         val payload = buildJsonObject {
-            put("type", "inventory_updated")
+            put("type", "inventoryUpdated")
             put("itemId", itemId)
             put("timestamp", System.currentTimeMillis())
         }
@@ -35,7 +35,7 @@ internal class WebSocketManager {
 
     suspend fun notifyFullSyncRequired(userId: String) {
         val payload = buildJsonObject {
-            put("type", "full_sync_required")
+            put("type", "fullSyncRequired")
             put("timestamp", System.currentTimeMillis())
         }
         broadcast(userId, Json.encodeToString(payload))