StemRoller: desktop stem separator, Android stems player, and server daemons

- stemroller/: PySide6/QML desktop app and player for separating music into stems
- android/: Plex music player that plays per-stem mixes, with Android Auto support,
  a graphic + parametric (Equalizer APO-style) EQ, and offline downloads
- server/: stemserve (serves stems to the app) and stemd (separates the library on
  the server's GPU, with "Stem Now" priority requests)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

stemroller/qml/StemRoller/GlassPanel.qml

@@ -0,0 +1,57 @@
+import QtQuick
+
+// Aero glass for chrome. Shows the window's cached, pre-blurred backdrop
+// (refreshed only on resize), so nothing is blurred per frame.
+Item {
+    id: root
+    property real offsetX: 0
+    property real offsetY: 0
+    property int blur: 16
+    property real topLeftRadius: 0
+    property real topRightRadius: 0
+    property real bottomLeftRadius: 0
+    property real bottomRightRadius: 0
+    property bool gloss: true
+    property bool innerBorder: true
+    clip: true
+
+    readonly property var win: Window.window
+
+    Image {
+        x: -root.offsetX
+        y: -root.offsetY
+        width: root.win ? root.win.width : 0
+        height: root.win ? root.win.height : 0
+        source: root.win ? "image://fx/glass/" + root.win.fxW + "x" + root.win.fxH + "/" + root.win.radius + "/" + root.blur : ""
+        asynchronous: true
+        retainWhileLoading: true
+        cache: true
+        smooth: true
+    }
+
+    // Aero gloss: top highlight band
+    Rectangle {
+        visible: root.gloss
+        anchors { left: parent.left; right: parent.right; top: parent.top }
+        height: Math.min(parent.height * 0.5, 30)
+        topLeftRadius: root.topLeftRadius
+        topRightRadius: root.topRightRadius
+        gradient: Gradient {
+            GradientStop { position: 0; color: Qt.rgba(1, 1, 1, 0.07) }
+            GradientStop { position: 1; color: Qt.rgba(1, 1, 1, 0.0) }
+        }
+    }
+
+    // 1px inner white border at 8%
+    Rectangle {
+        visible: root.innerBorder
+        anchors.fill: parent
+        color: "transparent"
+        border.color: Theme.outline
+        border.width: 1
+        topLeftRadius: root.topLeftRadius
+        topRightRadius: root.topRightRadius
+        bottomLeftRadius: root.bottomLeftRadius
+        bottomRightRadius: root.bottomRightRadius
+    }
+}