Rename everything to Stemify, and add a README

- Python package stemroller/ -> stemify/, Android package com.stemroller.mobile ->
  com.stemify.mobile, app names, QML module, icons, desktop entries, MPRIS and Plex
  product names
- Done-markers are now .stemify.json; stemd renames the old ones once at startup so
  songs separated before the rename aren't separated again
- A top-level README covering the server, the Android and Android Auto app, the EQ,
  Stem Now and the desktop apps

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

stemify/qml/Stemify/StemLane.qml

@@ -0,0 +1,147 @@
+import QtQuick
+import QtQuick.Controls.Basic
+
+// One lane per stem: color strip, solo / mute / gain / export, waveform texture.
+Item {
+    id: lane
+    required property int index
+    required property var modelData
+    property string jobId: ""
+    property real viewStart: 0
+    property real viewEnd: 1
+    property int waveW: 100
+    property int waveH: 60
+    property real waveX: 0
+    property bool anySolo: false
+    property bool solo: false
+    property bool mute: false
+    property real gainDb: 0
+    signal soloToggled(bool on)
+    readonly property string stem: modelData.name
+    readonly property color tone: modelData.color
+    readonly property bool audible: anySolo ? solo : !mute
+    height: 92
+
+    Card {
+        anchors.fill: parent
+        clip: false
+
+        // color strip with soft glow
+        Rectangle {
+            x: 0
+            width: 4
+            height: parent.height
+            topLeftRadius: 8
+            bottomLeftRadius: 8
+            color: lane.tone
+        }
+        Rectangle {
+            x: 4
+            width: 24
+            height: parent.height
+            gradient: Gradient {
+                orientation: Gradient.Horizontal
+                GradientStop { position: 0; color: Theme.alpha(lane.tone, 0.14) }
+                GradientStop { position: 1; color: Theme.alpha(lane.tone, 0.0) }
+            }
+        }
+
+        Column {
+            id: controls
+            x: 18
+            width: lane.waveX - 30
+            anchors.verticalCenter: parent.verticalCenter
+            spacing: 6
+            Row {
+                spacing: 6
+                width: parent.width
+                Txt {
+                    width: parent.width - 3 * 30 - 12
+                    text: lane.stem.charAt(0).toUpperCase() + lane.stem.slice(1)
+                    font.pixelSize: Theme.fs16
+                    font.weight: Font.DemiBold
+                    anchors.verticalCenter: parent.verticalCenter
+                }
+                IconButton {
+                    size: 30; iconSize: 16
+                    iconName: "headphones"
+                    checkable: true
+                    checked: lane.solo
+                    activeColor: Theme.warning
+                    tip: "Solo"
+                    onClicked: lane.soloToggled(checked)
+                }
+                IconButton {
+                    size: 30; iconSize: 16
+                    iconName: lane.mute ? "volume_off" : "volume"
+                    checkable: true
+                    checked: lane.mute
+                    activeColor: Theme.error
+                    tip: "Mute"
+                    onClicked: { lane.mute = checked; audio.setMute(lane.index, checked) }
+                }
+                IconButton {
+                    size: 30; iconSize: 16
+                    iconName: "download"
+                    tip: "Export " + lane.stem
+                    onClicked: app.exportStem(lane.stem)
+                }
+            }
+            Row {
+                spacing: 8
+                width: parent.width
+                AeroSlider {
+                    id: gain
+                    width: parent.width - 52
+                    from: -24
+                    to: 12
+                    stepSize: 0.5
+                    value: lane.gainDb
+                    tone: lane.tone
+                    onMoved: { lane.gainDb = value; audio.setGain(lane.index, value) }
+                    // double-click resets to unity
+                    TapHandler { onDoubleTapped: { lane.gainDb = 0; audio.setGain(lane.index, 0) } }
+                }
+                Txt {
+                    width: 44
+                    anchors.verticalCenter: parent.verticalCenter
+                    horizontalAlignment: Text.AlignRight
+                    text: (lane.gainDb > 0 ? "+" : "") + lane.gainDb.toFixed(1) + " dB"
+                    font.pixelSize: 11
+                    font.features: { "tnum": 1 }
+                    color: lane.gainDb === 0 ? Theme.textLo : Theme.textHi
+                }
+            }
+        }
+
+        Rectangle {  // waveform well
+            x: lane.waveX
+            y: 8
+            width: lane.waveW
+            height: parent.height - 16
+            radius: 6
+            color: Qt.rgba(0, 0, 0, 0.22)
+            border.color: Qt.rgba(1, 1, 1, 0.04)
+            Rectangle {
+                anchors.verticalCenter: parent.verticalCenter
+                width: parent.width
+                height: 1
+                color: Theme.alpha(lane.tone, 0.18)
+            }
+            Image {
+                anchors.fill: parent
+                asynchronous: true
+                retainWhileLoading: true
+                cache: false
+                smooth: true
+                opacity: lane.audible ? 1 : 0.28
+                Behavior on opacity { NumberAnimation { duration: Theme.med } }
+                source: lane.jobId && lane.waveW > 4
+                        ? "image://wave/" + lane.jobId + "/" + lane.stem + "/"
+                          + Math.round(lane.waveW * Screen.devicePixelRatio) + "x" + Math.round((lane.height - 16) * Screen.devicePixelRatio)
+                          + "/" + lane.viewStart.toFixed(3) + "/" + lane.viewEnd.toFixed(3) + "/" + Theme.hex(lane.tone)
+                        : ""
+            }
+        }
+    }
+}