lock: add blinking cursor for text input

fixes #2316

quickshell/Widgets/DankTextCursor.qml

@@ -0,0 +1,31 @@
+import QtQuick
+import qs.Common
+
+Rectangle {
+    id: root
+
+    property bool shown: true
+    property bool blinkOn: true
+
+    readonly property int flashTime: Qt.styleHints.cursorFlashTime
+
+    function resetBlink() {
+        blinkOn = true;
+        blinkTimer.restart();
+    }
+
+    width: 2
+    radius: 1
+    color: Theme.primary
+    visible: shown && blinkOn
+
+    onShownChanged: resetBlink()
+
+    Timer {
+        id: blinkTimer
+        running: root.shown && root.flashTime > 1
+        interval: root.flashTime / 2
+        repeat: true
+        onTriggered: root.blinkOn = !root.blinkOn
+    }
+}