Restyle Quickshell settings inputs to match Omarchy aesthetic

Settings dialogs were rendering text/spin/combo controls with Qt's
default light style, which clashed with the dark Omarchy theme — black
text on dark fills, white dropdown popups, rounded corners, and a
pill-style toggle that didn't match the native StyleToggleRow switch.

- Style.qml: collapse all radius tokens to 0 so Noctalia-compat widgets
  inherit Omarchy's sharp-corner convention
- NToggle: rewrite to mirror the native 48x22 switch with accent fill
  and a sliding 16x16 thumb
- NComboBox: skin contentItem, indicator, popup, and delegate so the
  dropdown reads on dark themes
- NSpinBox: add a styled background, contentItem, and up/down indicators
- SettingsPanel calendar form + DynamicSettingsForm string field: drop
  default TextField chrome for the same translucent foreground fill used
  by WidgetCard, accent border on focus

default/quickshell/omarchy-shell/plugins/settings/SettingsPanel.qml

@@ -2600,18 +2600,40 @@ Item {
       spacing: 8
       width: parent ? parent.width : 0
 
+      component CalendarField: TextField {
+        id: calField
+        property string fieldKey: ""
+        font.family: root.fontFamily
+        font.pixelSize: 12
+        width: parent.width
+        color: root.foreground
+        selectionColor: Qt.rgba(root.foreground.r, root.foreground.g, root.foreground.b, 0.35)
+        selectedTextColor: root.foreground
+        placeholderTextColor: Qt.darker(root.foreground, 1.6)
+        leftPadding: 10
+        rightPadding: 10
+        topPadding: 7
+        bottomPadding: 7
+        onEditingFinished: if (fieldKey) calForm.fieldChanged(fieldKey, text)
+        background: Rectangle {
+          color: Qt.rgba(root.foreground.r, root.foreground.g, root.foreground.b,
+                         calField.activeFocus ? 0.08 : 0.04)
+          border.color: calField.activeFocus
+            ? Qt.rgba(root.foreground.r, root.foreground.g, root.foreground.b, 0.4)
+            : Qt.rgba(root.foreground.r, root.foreground.g, root.foreground.b, 0.18)
+          border.width: 1
+        }
+      }
+
       Text {
         text: "Horizontal format"
         color: Qt.darker(root.foreground, 1.4)
         font.family: root.fontFamily
         font.pixelSize: 11
       }
-      TextField {
+      CalendarField {
+        fieldKey: "format"
         text: calForm.entry.format || "dddd HH:mm"
-        font.family: root.fontFamily
-        font.pixelSize: 12
-        width: parent.width
-        onEditingFinished: calForm.fieldChanged("format", text)
       }
 
       Text {
@@ -2620,12 +2642,9 @@ Item {
         font.family: root.fontFamily
         font.pixelSize: 11
       }
-      TextField {
+      CalendarField {
+        fieldKey: "formatAlt"
         text: calForm.entry.formatAlt || "dd MMMM 'W'ww yyyy"
-        font.family: root.fontFamily
-        font.pixelSize: 12
-        width: parent.width
-        onEditingFinished: calForm.fieldChanged("formatAlt", text)
       }
 
       Text {
@@ -2634,12 +2653,9 @@ Item {
         font.family: root.fontFamily
         font.pixelSize: 11
       }
-      TextField {
+      CalendarField {
+        fieldKey: "verticalFormat"
         text: calForm.entry.verticalFormat || "HH\n—\nmm"
-        font.family: root.fontFamily
-        font.pixelSize: 12
-        width: parent.width
-        onEditingFinished: calForm.fieldChanged("verticalFormat", text)
       }
     }
   }