fix: KF6Attica recipe, kf6-knewstuff Attica dep, topo-sort cycle error

- Created kf6-attica recipe (minimal core library build providing
  KF6::Attica cmake target, needed by kf6-knewstuff). v6.10.0,
  QML/tests/examples disabled.
- Added kf6-attica to redbear-full.toml config, integrate-redbear.sh
  symlink, and recipes/kde/ symlink.
- Fixed kf6-knewstuff: removed stale find_package(KF6Attica)
  suppression; added kf6-attica as dependency. Now publishes
  to repo (core-only build produces empty package — upstream
  code structure yields no libs with QtQuick/widgets/tools off).
- Cookbook topo-sort: changed cycle fallback from silent
  Ok(recipes) to Err(Recursion) — surfaces dependency graph
  bugs instead of hiding them.
- Fixed stale QtNetwork comment: QtNetwork IS enabled in qtbase
  since 2026-04-29 (relibc DNS resolver hardened).
- Verified: kf6-attica builds, kf6-knewstuff publishes to repo

local/recipes/kde/kf6-attica/source/src/listjob.cpp

@@ -0,0 +1,36 @@
+/*
+    This file is part of KDE.
+
+    SPDX-FileCopyrightText: 2009 Eckhart Wörner <ewoerner@kde.org>
+
+    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
+*/
+
+#include "listjob.h"
+
+#include <QXmlStreamReader>
+#include <attica_debug.h>
+
+using namespace Attica;
+
+template<class T>
+ListJob<T>::ListJob(PlatformDependent *internals, const QNetworkRequest &request)
+    : GetJob(internals, request)
+{
+    qCDebug(ATTICA) << "creating list job:" << request.url();
+}
+
+template<class T>
+typename T::List ListJob<T>::itemList() const
+{
+    return m_itemList;
+}
+
+template<class T>
+void ListJob<T>::parse(const QString &xml)
+{
+    typename T::Parser parser;
+    m_itemList = parser.parseList(xml);
+    setMetadata(parser.metadata());
+    qCDebug(ATTICA) << "received categories:" << m_itemList.size();
+}