feat(quickshell): add hyprchrome bar with collapsible panels

A second shell chrome under dotfiles/quickshell/hyprchrome, built around a
BarPanel that carries TWO renderings of its data: the default children are the
expanded detail view, `summary` the terse one shown while collapsed. Both stay
bound to the same sources, so the densities cannot disagree, and the panel
cross-fades between them while its height animates.

Panels: HostPanel (hostname, user, timezone, clock), VitalsPanel (CPU load and
temperature, memory, GPU load and temperature, all metered), TrayPanel (system
tray, self-sizing). HyprChromeBar pins them to DP-2 and owns `expanded` for the
whole rail — SUPER A, via GlobalShortcut "chrome".

GPU busy comes off sysfs rather than the node_exporter scrape VitalsData
already does: the hwmon collector carries the card's temps, power and clocks
but not its utilisation.

The bar's height binds to each panel's `targetHeight` — where it will settle,
not where the animation currently is — because the exclusive zone is
window-sized by default, and binding to the animated height relayouts every
tiled window on the output twelve times per toggle. The zone follows the target
immediately so the desktop reflows once, at the start; the surface itself
shrinks only after the panels finish, or it would clip them mid-animation.

DebugWindow stages a widget in the middle of the secondary monitor
(SUPER CTRL D), masked so only the staged widget takes pointer input.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HEtXvseVb5gwAtKNhFx2PU

dotfiles/quickshell/hyprchrome/widgets/vitals/SegmentMeter.qml

@@ -0,0 +1,40 @@
+pragma ComponentBehavior: Bound
+
+import QtQuick
+import qs.hyprchrome.theme
+
+// Segmented horizontal meter: a row of cells lit up to `value`.
+//
+// A copy of the dense bar's meter rather than a reuse of it — that one is an
+// inline component inside DenseBarContent.qml and so is not visible from any
+// other file (the same reason BarPanel inlines its own MicroText).
+Row {
+    id: meter
+
+    property int segments: 16
+    property real value: 0        // 0..1
+    property bool ready: false
+    property real warn: 0.85      // fraction at which the lit cells go hot
+
+    readonly property real fraction: Math.max(0, Math.min(1, meter.value))
+    readonly property bool hot: meter.ready && meter.fraction >= meter.warn
+    readonly property color litColor: meter.hot ? Theme.hot : Theme.accent
+
+    spacing: 2
+
+    Repeater {
+        model: meter.segments
+
+        Rectangle {
+            required property int index
+
+            readonly property bool lit: meter.ready && index < Math.round(meter.fraction * meter.segments)
+
+            width: Math.max(2, (meter.width - (meter.segments - 1) * meter.spacing) / meter.segments)
+            height: meter.height
+            color: lit ? meter.litColor : Theme.textAlpha(0.06)
+            border.width: 1
+            border.color: lit ? meter.litColor : Theme.textAlpha(0.18)
+        }
+    }
+}