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/PillButton.qml

@@ -8,15 +8,15 @@ Rectangle {
   property string text: ""
   property string iconText: ""
   property string tooltipText: ""
-  property color foreground: "#cacccc"
+  property color foreground: Color.foreground
   property color background: "transparent"
   property color hoverBackground: Qt.rgba(foreground.r, foreground.g, foreground.b, 0.08)
   property color pressedBackground: Qt.rgba(foreground.r, foreground.g, foreground.b, 0.22)
-  property color tooltipBackground: "#101315"
+  property color tooltipBackground: Color.background
   property color tooltipForeground: foreground
-  property string fontFamily: "JetBrainsMono Nerd Font"
-  property real fontSize: 12
-  property real iconSize: 14
+  property string fontFamily: Style.font.family
+  property real fontSize: Style.font.body
+  property real iconSize: Style.font.icon
   property real iconRotation: 0
   property real horizontalPadding: 10
   property real verticalPadding: 6
@@ -66,7 +66,7 @@ Rectangle {
       text: root.tooltipText
       color: root.tooltipForeground
       font.family: root.fontFamily
-      font.pixelSize: 11
+      font.pixelSize: Style.font.bodySmall
       leftPadding: 10
       rightPadding: 10
       topPadding: 6