v1.4.0: digit-only flaps with white euro text, nixie white euro + configurable flicker, mode-conditional config fields; fix stale derived-property reads in change handler

contents/ui/configGeneral.qml

@@ -2,6 +2,7 @@
  * Config page for nl.a14r.bitcoinprice.
  * Follows the canonical Plasma 5 config dialog pattern:
  * Kirigami.FormLayout + cfg_ prefixed property aliases.
+ * Mode-specific settings are only visible for the matching style.
  */
 
 import QtQuick 2.15
@@ -15,6 +16,7 @@ Kirigami.FormLayout {
     property alias cfg_displayMode: modeCombo.currentIndex
     property alias cfg_refreshMinutes: intervalSpin.value
     property alias cfg_flapSeconds: flapSpin.value
+    property alias cfg_nixieFlicker: flickSpin.value
 
     Item {
         Kirigami.FormData.isSection: true
@@ -28,6 +30,7 @@ Kirigami.FormLayout {
 
     QQC2.SpinBox {
         id: flapSpin
+        visible: modeCombo.currentIndex === 1
         Kirigami.FormData.label: i18n("Split-flap cascade (seconds):")
         from: 1
         to: 15
@@ -35,6 +38,16 @@ Kirigami.FormLayout {
         editable: true
     }
 
+    QQC2.SpinBox {
+        id: flickSpin
+        visible: modeCombo.currentIndex === 2
+        Kirigami.FormData.label: i18n("Nixie flicker (0 = off):")
+        from: 0
+        to: 100
+        stepSize: 10
+        editable: true
+    }
+
     QQC2.SpinBox {
         id: intervalSpin
         Kirigami.FormData.label: i18n("Refresh interval (minutes):")