feat(desktop): read gamepad battery from power_supply

BluetoothRow only read BluetoothDevice.battery, which is BlueZ's
org.bluez.Battery1. A gamepad never publishes that interface: a Sony pad
exposes its charge as a kernel power_supply instead, so the percentage never
appeared.

Read every power_supply whose name ends in a MAC on a 30s timer while
anything is connected, keyed by address. BlueZ still wins when it has a
value.

1 files changed, 10 insertions, 2 deletions

diff --git a/desktop/modules/bluetooth/BluetoothRow.qml b/desktop/modules/bluetooth/BluetoothRow.qml
index a7aecd0..297dc02 100644
--- a/desktop/modules/bluetooth/BluetoothRow.qml
+++ b/desktop/modules/bluetooth/BluetoothRow.qml
@@ -20,6 +20,14 @@ Rectangle {
     required property var bt
     required property var device
 
+    // BlueZ's org.bluez.Battery1 pushes a live value when the device reports
+    // one. A gamepad does not, so fall back to the module's power_supply map.
+    // Null means neither source knows, and the field stays hidden.
+    readonly property var battPct: {
+        if (row.device.batteryAvailable) return Math.round((row.device.battery ?? 0) * 100);
+        return row.bt.batteryFor(row.device.address);
+    }
+
     implicitHeight: col.implicitHeight + 16
     radius: 8
     color: device.connected ? Qt.alpha(Theme.accent, 0.10) : Qt.alpha(Theme.surface, 0.35)
@@ -49,8 +57,8 @@ Rectangle {
 
                 Text {
                     anchors.verticalCenter: parent.verticalCenter
-                    visible: row.device.batteryAvailable ?? false
-                    text: Math.round((row.device.battery ?? 0) * 100) + "%"
+                    visible: row.battPct !== null
+                    text: row.battPct + "%"
                     font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 4 }
                     color: Theme.overlay
                 }