v0.1.2: Preferences page, About page, full icon set, redesigned edit form

- Rework the add/edit form onto a generic, catalog-driven field model
  (JobFieldCatalog + JobEditModel), replacing the old hand-written
  ApplicationEditDialog with ApplicationEditPage
- Add a Preferences page (reachable from the hamburger menu) with a
  KColorSchemeManager-backed color scheme switcher
- Add an About page reading from KAboutData
- Ship a full hicolor icon set (16-128px + scalable) via ecm_install_icons
  instead of a single flat SVG
- Restyle the edit form after KDE System Settings' Audio page:
  Kirigami.ListSectionHeader per category, flat separated rows, no card
  borders
- Explicitly declare Kirigami/KirigamiAddons/ColorScheme as CMake
  dependencies instead of relying on the QML import scanner alone
- Add KDEClangFormat/KDEGitCommitHooks, a CMakePresets.json, and a
  REUSE + clang-format lint CI workflow
- Reformat SPDX headers to include copyright, remove debug screenshot
  scaffolding

src/appcolorscheme.h

@@ -0,0 +1,40 @@
+/*
+    SPDX-FileCopyrightText: 2026 ToServeTheKing <[email protected]>
+
+    SPDX-License-Identifier: GPL-3.0-or-later
+*/
+
+#pragma once
+
+#include <QAbstractItemModel>
+#include <QObject>
+#include <QQmlEngine>
+
+class KColorSchemeManager;
+
+/**
+ * Thin QML-facing wrapper around KColorSchemeManager: exposes the list of
+ * installed color schemes and the currently active one. KColorSchemeManager
+ * autosaves the active scheme itself, so there is nothing else to persist.
+ */
+class AppColorScheme : public QObject
+{
+    Q_OBJECT
+    QML_ELEMENT
+    QML_SINGLETON
+    Q_PROPERTY(QAbstractItemModel *colorSchemesModel READ colorSchemesModel CONSTANT)
+    Q_PROPERTY(QString activeColorSchemeName READ activeColorSchemeName WRITE setActiveColorSchemeName NOTIFY activeColorSchemeNameChanged)
+
+public:
+    explicit AppColorScheme(QObject *parent = nullptr);
+
+    QAbstractItemModel *colorSchemesModel();
+    QString activeColorSchemeName() const;
+    void setActiveColorSchemeName(const QString &name);
+
+Q_SIGNALS:
+    void activeColorSchemeNameChanged();
+
+private:
+    KColorSchemeManager *mSchemes;
+};