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/Ui/SearchableDropdown.qml

@@ -29,7 +29,7 @@ Item {
   property color background: Color.popups.background
   property color popupBorder: Color.popups.border
   property color accent: Color.accent
-  property string fontFamily: "JetBrainsMono Nerd Font"
+  property string fontFamily: Style.font.family
   property int rowHeight: 28
   property int popupRowHeight: 28
   property int popupMinHeight: 220
@@ -96,7 +96,7 @@ 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
     }
 
@@ -140,7 +140,7 @@ Item {
         text: root.currentLabel() || root.triggerLabel || root.placeholderText
         color: (root.currentLabel() || root.triggerLabel) ? root.foreground : Qt.darker(root.foreground, 1.5)
         font.family: root.fontFamily
-        font.pixelSize: 12
+        font.pixelSize: Style.font.body
         elide: Text.ElideRight
       }
 
@@ -152,7 +152,7 @@ Item {
         text: "󰅀"
         color: Qt.darker(root.foreground, 1.2)
         font.family: root.fontFamily
-        font.pixelSize: 12
+        font.pixelSize: Style.font.body
       }
 
       MouseArea {
@@ -204,7 +204,7 @@ Item {
               foreground: root.foreground
               accent: root.accent
               font.family: root.fontFamily
-              font.pixelSize: 12
+              font.pixelSize: Style.font.body
 
               onTextChanged: {
                 root.recomputeFiltered()
@@ -247,7 +247,7 @@ Item {
               text: root.emptyText
               color: Qt.darker(root.foreground, 1.6)
               font.family: root.fontFamily
-              font.pixelSize: 12
+              font.pixelSize: Style.font.body
             }
 
             ListView {
@@ -312,7 +312,7 @@ Item {
                     text: root.optionLabel(modelData)
                     color: index === resultList.currentIndex ? root.accent : root.foreground
                     font.family: root.fontFamily
-                    font.pixelSize: 12
+                    font.pixelSize: Style.font.body
                     elide: Text.ElideRight
                     width: parent.width
                   }
@@ -321,7 +321,7 @@ Item {
                     text: root.optionDescription(modelData)
                     color: Qt.darker(root.foreground, 1.5)
                     font.family: root.fontFamily
-                    font.pixelSize: 10
+                    font.pixelSize: Style.font.caption
                     elide: Text.ElideRight
                     width: parent.width
                   }