fix contractor upload with image

composeApp/src/commonMain/kotlin/com/example/mycrib/network/TaskCompletionApi.kt

@@ -109,6 +109,7 @@ class TaskCompletionApi(private val client: HttpClient = ApiClient.httpClient) {
                         io.ktor.client.request.forms.formData {
                             // Add text fields
                             append("task", request.task.toString())
+                            request.contractor?.let { append("contractor", it.toString()) }
                             request.completedByName?.let { append("completed_by_name", it) }
                             append("completion_date", request.completionDate)
                             request.actualCost?.let { append("actual_cost", it) }