Unify font sizes through qs.Commons.Style

Themes now drive typography the same way they drive colors: one [font]
base-size in shell.toml is the rem root, and every Style.font.<token>
(caption, bodySmall, body, subtitle, title, heading, display,
displayLarge, iconSmall, icon, iconLarge) derives from it via a fixed
multiplier. Themes can also pin individual tokens for stylistic
emphasis. base-size is clamped 11..13 until row-height tokens exist.

Bar dimensions move to the same singleton: [bar] size-horizontal /
size-vertical replace the hardcoded 26/28 in Bar.qml, exposed as
Style.bar.sizeHorizontal / sizeVertical.

Style.qml also resolves the fontconfig 'monospace' alias via fc-match
and exposes Style.font.resolvedFamily so panels can display the
concrete family. Watches ~/.config/fontconfig/fonts.conf so it tracks
'omarchy font set <name>'.

The qs.Ui kit (PillButton, Dropdown, Toggle, TextField, etc.) and
every first-party plugin (bar widgets, settings, menu, clipboard,
emoji, polkit, notifications, osd, image-picker, dev-gallery) now
bind to Style.font.* instead of pixel literals. Only three deliberate
display-scale outliers remain: the notification empty-state glyph and
the weather flyout's hero temperature pair, all commented.

Background plugin's applyTheme IPC fast-path also pushes shell.toml to
Style so theme swaps update typography and bar size without waiting
for inotify debounce.

Dev gallery (omarchy dev ui-preview) now ships a Typography section
that renders the full scale and theme tokens live, and its summon
command is fixed (omarchy-shell-ipc -> omarchy-shell).

shell/plugins/settings/components/NDropdown.qml

@@ -1,5 +1,6 @@
 import QtQuick
 import QtQuick.Controls
+import qs.Commons
 
 // Themed ComboBox + popup. Anchors below the trigger, paints with the host
 // shell's foreground/background palette, and inherits the shell-wide corner
@@ -10,10 +11,10 @@ Item {
   property string label: ""
   property string value: ""
   property var options: []
-  property color foreground: "#cacccc"
-  property color background: "#101315"
-  property color accent: "#cacccc"
-  property string fontFamily: "monospace"
+  property color foreground: Color.foreground
+  property color background: Color.background
+  property color accent: Color.accent
+  property string fontFamily: Style.font.family
   property int cornerRadius: 0
   property int rowHeight: 28
   property int popupRowHeight: 28
@@ -33,7 +34,7 @@ Item {
       text: root.label
       color: Qt.darker(root.foreground, 1.4)
       font.family: root.fontFamily
-      font.pixelSize: 10
+      font.pixelSize: Style.font.caption
       font.bold: true
     }
 
@@ -42,7 +43,7 @@ Item {
       width: parent.width
       height: root.rowHeight
       font.family: root.fontFamily
-      font.pixelSize: 12
+      font.pixelSize: Style.font.body
       model: root.options
       currentIndex: {
         for (var i = 0; i < model.length; i++) if (model[i] === root.value) return i
@@ -76,7 +77,7 @@ Item {
         text: "▾"
         color: Qt.darker(root.foreground, 1.2)
         font.family: root.fontFamily
-        font.pixelSize: 10
+        font.pixelSize: Style.font.caption
       }
 
       popup: Popup {
@@ -115,7 +116,7 @@ Item {
           text: String(modelData)
           color: index === combo.highlightedIndex ? root.accent : root.foreground
           font.family: root.fontFamily
-          font.pixelSize: 12
+          font.pixelSize: Style.font.body
           leftPadding: 10
           rightPadding: 10
           verticalAlignment: Text.AlignVCenter