refactor: Restructure project into sources/tests layout and dissolve PluginLLMCore

sources/UIControls/qml/QoAButton.qml

@@ -0,0 +1,54 @@
+// Copyright (C) 2024-2026 Petr Mironychev
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Additional attribution terms under GPLv3 §7(b) apply — see LICENSE
+
+import QtQuick
+import QtQuick.Controls.Basic
+
+Button {
+    id: control
+
+    property color accentColor: "transparent"
+
+    focusPolicy: Qt.NoFocus
+    padding: 4
+
+    icon.width: 16
+    icon.height: 16
+
+    contentItem.height: 20
+
+    background: Rectangle {
+        id: bg
+
+        readonly property bool hasAccent: control.accentColor.a > 0
+
+        implicitHeight: 20
+
+        color: !control.enabled || !control.down ? control.palette.button : control.palette.dark
+        border.color: bg.hasAccent
+                      ? control.accentColor
+                      : (!control.enabled || (!control.hovered && !control.visualFocus) ? control.palette.mid : control.palette.highlight)
+        border.width: bg.hasAccent ? 2 : 1
+        radius: 4
+
+        Rectangle {
+            anchors.fill: bg
+            radius: bg.radius
+            gradient: Gradient {
+                GradientStop { position: 0.0; color: Qt.alpha(control.palette.highlight, 0.4) }
+                GradientStop { position: 1.0; color: Qt.alpha(control.palette.highlight, 0.2) }
+            }
+            opacity: control.hovered ? 0.3 : 0.01
+            Behavior on opacity {NumberAnimation{duration: 250}}
+        }
+
+        Rectangle {
+            anchors.fill: bg
+            radius: bg.radius
+            color: control.accentColor
+            visible: bg.hasAccent
+            opacity: 0.15
+        }
+    }
+}