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/AeroSwitch.qml

@@ -0,0 +1,43 @@
+import QtQuick
+import QtQuick.Controls.Basic
+
+Switch {
+    id: sw
+    hoverEnabled: true
+    font.family: Theme.fontFamily
+    font.pixelSize: Theme.fs14
+    spacing: 12
+    indicator: Rectangle {
+        implicitWidth: 40
+        implicitHeight: 22
+        x: sw.leftPadding
+        y: parent.height / 2 - height / 2
+        radius: 11
+        color: sw.checked ? Theme.primary : Qt.rgba(1, 1, 1, 0.10)
+        border.color: sw.checked ? Qt.lighter(Theme.primary, 1.3) : Qt.rgba(1, 1, 1, 0.16)
+        Behavior on color { ColorAnimation { duration: Theme.med } }
+        Glow { radius: 11; sigma: 4; opacity: sw.hovered ? 0.35 : 0 }
+        Rectangle {
+            x: sw.checked ? parent.width - width - 3 : 3
+            anchors.verticalCenter: parent.verticalCenter
+            width: 16
+            height: 16
+            radius: 8
+            color: "#FFFFFF"
+            Behavior on x { NumberAnimation { duration: Theme.med; easing.type: Easing.BezierSpline; easing.bezierCurve: Theme.ease } }
+            Rectangle {
+                anchors { left: parent.left; right: parent.right; top: parent.top; margins: 2 }
+                height: 6
+                radius: 3
+                color: Qt.rgba(1, 1, 1, 0.6)
+            }
+        }
+    }
+    contentItem: Txt {
+        text: sw.text
+        font: sw.font
+        leftPadding: sw.indicator.width + sw.spacing
+        wrapMode: Text.WordWrap
+        elide: Text.ElideNone
+    }
+}