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/NToggle.qml

@@ -18,21 +18,25 @@ Rectangle {
 
   Rectangle {
     id: indicator
-    width: 32
-    height: 18
+    width: 48
+    height: 22
     anchors.verticalCenter: parent.verticalCenter
-    radius: height / 2
-    color: root.checked ? Color.mPrimary : Color.mSurfaceVariant
-    border.color: Color.mOutline
+    radius: 0
+    color: root.checked
+      ? Color.mPrimary
+      : Qt.rgba(Color.mOnSurface.r, Color.mOnSurface.g, Color.mOnSurface.b, 0.10)
+    border.color: root.checked
+      ? Color.mPrimary
+      : Qt.rgba(Color.mOnSurface.r, Color.mOnSurface.g, Color.mOnSurface.b, 0.4)
     border.width: Style.borderS
 
     Rectangle {
-      x: root.checked ? parent.width - width - 2 : 2
-      y: 2
-      width: parent.height - 4
-      height: parent.height - 4
-      radius: height / 2
-      color: Color.mOnSurface
+      width: 16
+      height: 16
+      radius: 0
+      anchors.verticalCenter: parent.verticalCenter
+      x: root.checked ? parent.width - width - 3 : 3
+      color: root.checked ? Color.mSurface : Color.mOnSurface
       Behavior on x { NumberAnimation { duration: Style.animationFast } }
     }
   }