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/Widgets/NComboBox.qml

@@ -17,6 +17,11 @@ ComboBox {
   valueRole: "key"
   font.family: "JetBrainsMono Nerd Font"
   font.pixelSize: Style.fontSizeS
+  implicitHeight: 32
+  leftPadding: 10
+  rightPadding: 28
+  topPadding: 4
+  bottomPadding: 4
 
   function itemAt(index) {
     if (index < 0) return null
@@ -55,10 +60,79 @@ ComboBox {
     root.selected(key, item)
   }
 
+  contentItem: Text {
+    text: root.displayText
+    color: Color.mOnSurface
+    font: root.font
+    verticalAlignment: Text.AlignVCenter
+    elide: Text.ElideRight
+  }
+
   background: Rectangle {
     color: Color.mSurfaceVariant
-    border.color: Color.mOutline
+    border.color: root.activeFocus ? Color.mPrimary : Color.mOutline
     border.width: Style.borderS
-    radius: Style.radiusS
+    radius: 0
+  }
+
+  indicator: Text {
+    x: root.width - width - 10
+    y: (root.height - height) / 2
+    text: "▾"
+    color: Color.mOnSurfaceVariant
+    font.family: root.font.family
+    font.pixelSize: 11
+  }
+
+  delegate: ItemDelegate {
+    id: del
+    required property int index
+    required property var modelData
+    width: ListView.view ? ListView.view.width : root.width
+    height: 28
+    highlighted: root.highlightedIndex === del.index
+
+    contentItem: Text {
+      text: {
+        var m = del.modelData
+        if (m === null || m === undefined) return ""
+        if (root.textRole && m[root.textRole] !== undefined) return String(m[root.textRole])
+        return String(m)
+      }
+      color: Color.mOnSurface
+      font: root.font
+      verticalAlignment: Text.AlignVCenter
+      elide: Text.ElideRight
+    }
+
+    background: Rectangle {
+      color: del.highlighted || del.hovered
+        ? Qt.rgba(Color.mOnSurface.r, Color.mOnSurface.g, Color.mOnSurface.b, 0.14)
+        : "transparent"
+      radius: 0
+    }
+  }
+
+  popup: Popup {
+    y: root.height
+    width: root.width
+    implicitHeight: Math.min(contentItem.implicitHeight + 2, 280)
+    padding: 1
+
+    background: Rectangle {
+      color: Color.mSurface
+      border.color: Color.mOutline
+      border.width: Style.borderS
+      radius: 0
+    }
+
+    contentItem: ListView {
+      clip: true
+      implicitHeight: contentHeight
+      model: root.popup.visible ? root.delegateModel : null
+      currentIndex: root.highlightedIndex
+      boundsBehavior: Flickable.StopAtBounds
+      ScrollIndicator.vertical: ScrollIndicator { }
+    }
   }
 }