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/clipboard-picker/ClipboardPicker.qml

@@ -241,7 +241,7 @@ Item {
             color: root.foreground
             opacity: root.filterText ? 1 : 0.58
             font.family: root.fontFamily
-            font.pixelSize: 16
+            font.pixelSize: Style.font.heading
             elide: Text.ElideRight
           }
         }
@@ -299,7 +299,7 @@ Item {
                     text: parent.parent.isPassword ? "••••••••" : (parent.parent.previewType === "text" ? parent.parent.previewText : "Image")
                     color: index === root.selectedIndex ? root.accent : root.foreground
                     font.family: root.fontFamily
-                    font.pixelSize: 14
+                    font.pixelSize: Style.font.title
                     font.italic: parent.parent.previewType === "file" || parent.parent.isPassword
                     opacity: (parent.parent.previewType === "file" || parent.parent.isPassword) ? 0.6 : 1.0
                     elide: Text.ElideRight
@@ -339,7 +339,7 @@ Item {
                 text: parent.activeRow ? (parent.activeRow.isPassword ? "••••••••" : parent.activeRow.previewText) : ""
                 color: root.foreground
                 font.family: root.fontFamily
-                font.pixelSize: 14
+                font.pixelSize: Style.font.title
                 wrapMode: Text.WrapAnywhere
                 elide: Text.ElideRight
                 verticalAlignment: Text.AlignTop
@@ -365,7 +365,7 @@ Item {
               color: root.accent
               opacity: 0.8
               font.family: root.fontFamily
-              font.pixelSize: 28
+              font.pixelSize: Style.font.displayLarge
               horizontalAlignment: Text.AlignHCenter
               width: parent.width
             }
@@ -375,7 +375,7 @@ Item {
               color: root.foreground
               opacity: 0.7
               font.family: root.fontFamily
-              font.pixelSize: 14
+              font.pixelSize: Style.font.title
               horizontalAlignment: Text.AlignHCenter
               width: parent.width
             }