feat(quickshell): "Take your time." glows and flickers

A new GlowText component lights a line from inside: a soft two-layer
halo that breathes slowly, and every 4-14 seconds a short, uneven
stutter like a tube catching. Only opacity and the halo move, so the
glyphs stay on the pixel grid. The lock screen and the power menu use
it; the power menu's stops while it is closed.

quickshell/components/GlowText.qml

@@ -0,0 +1,110 @@
+import QtQuick
+import QtQuick.Effects
+import "root:/config"
+
+// A line of type lit from inside, like a tube in a dark console: a soft halo
+// that breathes slowly, and every so often a short, uneven stutter where the
+// light catches — two or three dips, then steady again for a while. The
+// stutters come at random intervals so it never settles into a rhythm you
+// could count.
+//
+// Only the halo and the opacity move, never the geometry, so the glyphs stay
+// on the pixel grid. Set `active` false while the text is off screen to stop
+// the animation.
+Item {
+    id: root
+
+    property string text: ""
+    property color color: Theme.accent
+    property color glowColor: root.color
+    property string family: Theme.fontDisplay
+    property int pixelSize: Theme.fsLarge
+    property int weight: Font.Light
+    property real letterSpacing: 0
+    property bool active: true
+
+    // 0..1, how lit the tube is at this instant.
+    property real lit: 1
+    // Slow breathing on the halo alone, between `low` and 1.
+    property real breath: 1
+
+    implicitWidth: label.implicitWidth
+    implicitHeight: label.implicitHeight
+
+    Text {
+        id: label
+        visible: false
+        text: root.text
+        color: root.color
+        font.family: root.family
+        font.pixelSize: root.pixelSize
+        font.weight: root.weight
+        font.letterSpacing: root.letterSpacing
+        // Greyscale antialiasing: the glyphs are drawn into the effect's
+        // texture, and native subpixel rendering there leaves colour fringes.
+        renderType: Text.CurveRendering
+    }
+
+    // A wide, faint halo under a tight, brighter one, so the light both
+    // spreads into the dark and hugs the strokes.
+    MultiEffect {
+        source: label
+        anchors.fill: label
+        autoPaddingEnabled: true
+        opacity: root.lit
+
+        shadowEnabled: true
+        shadowColor: root.glowColor
+        shadowHorizontalOffset: 0
+        shadowVerticalOffset: 0
+        shadowBlur: 1.0
+        blurMax: Math.max(32, Math.round(root.pixelSize * 2))
+        shadowOpacity: 0.7 * root.breath
+        shadowScale: 1.02
+    }
+
+    MultiEffect {
+        source: label
+        anchors.fill: label
+        autoPaddingEnabled: true
+        opacity: 0.55 + 0.45 * root.lit
+
+        shadowEnabled: true
+        shadowColor: root.glowColor
+        shadowHorizontalOffset: 0
+        shadowVerticalOffset: 0
+        shadowBlur: 1.0
+        blurMax: Math.max(8, Math.round(root.pixelSize * 0.35))
+        shadowOpacity: 0.9 * root.lit
+    }
+
+    SequentialAnimation on breath {
+        running: root.active
+        loops: Animation.Infinite
+        NumberAnimation { to: 0.6; duration: 2600; easing.type: Easing.InOutSine }
+        NumberAnimation { to: 1.0; duration: 2600; easing.type: Easing.InOutSine }
+    }
+
+    // One stutter: uneven dips of uneven length, then back to full.
+    SequentialAnimation {
+        id: stutter
+        NumberAnimation { target: root; property: "lit"; to: 0.25; duration: 40 }
+        NumberAnimation { target: root; property: "lit"; to: 0.9; duration: 60 }
+        PauseAnimation { duration: 70 }
+        NumberAnimation { target: root; property: "lit"; to: 0.4; duration: 30 }
+        NumberAnimation { target: root; property: "lit"; to: 1.0; duration: 180; easing.type: Easing.OutCubic }
+    }
+
+    Timer {
+        id: nextStutter
+        running: root.active
+        repeat: true
+        interval: 6000
+        onTriggered: {
+            stutter.restart();
+            nextStutter.interval = 4000 + Math.random() * 10000;
+        }
+    }
+
+    onActiveChanged: if (!root.active) { stutter.stop(); root.lit = 1; }
+}