feat: Blink WiFi/Bluetooth icons while connecting (#2448)

Pulses the WiFi and Bluetooth status icons while a connection is in
progress (lock screen, DankBar control center button, control center
compound pill). The pulse is implemented as a reusable Widgets/DankBlink
component, and the wifi-connecting condition is centralized as
NetworkService.isWifiConnecting.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

quickshell/Widgets/DankBlink.qml

@@ -0,0 +1,28 @@
+import QtQuick
+
+SequentialAnimation {
+    id: root
+
+    property Item target
+    property real minOpacity: 0.3
+    property int pulseDuration: 600
+
+    loops: Animation.Infinite
+
+    NumberAnimation {
+        target: root.target
+        property: "opacity"
+        to: root.minOpacity
+        duration: root.pulseDuration
+        easing.type: Easing.InOutQuad
+    }
+    NumberAnimation {
+        target: root.target
+        property: "opacity"
+        to: 1.0
+        duration: root.pulseDuration
+        easing.type: Easing.InOutQuad
+    }
+
+    onStopped: if (root.target) root.target.opacity = 1.0
+}