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/homepageentry.cpp

@@ -0,0 +1,63 @@
+/*
+    This file is part of KDE.
+
+    SPDX-FileCopyrightText: 2010 Intel Corporation
+    SPDX-FileContributor: Mateu Batle Sastre <mbatle@collabora.co.uk>
+
+    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
+*/
+
+#include "homepageentry.h"
+
+using namespace Attica;
+
+class Q_DECL_HIDDEN HomePageEntry::Private : public QSharedData
+{
+public:
+    QString type;
+    QUrl url;
+
+    Private()
+    {
+    }
+};
+
+HomePageEntry::HomePageEntry()
+    : d(new Private)
+{
+}
+
+HomePageEntry::HomePageEntry(const Attica::HomePageEntry &other)
+    : d(other.d)
+{
+}
+
+HomePageEntry &HomePageEntry::operator=(const Attica::HomePageEntry &other)
+{
+    d = other.d;
+    return *this;
+}
+
+HomePageEntry::~HomePageEntry()
+{
+}
+
+QString HomePageEntry::type() const
+{
+    return d->type;
+}
+
+void HomePageEntry::setType(const QString &type)
+{
+    d->type = type;
+}
+
+QUrl HomePageEntry::url() const
+{
+    return d->url;
+}
+
+void HomePageEntry::setUrl(const QUrl &url)
+{
+    d->url = url;
+}