Make Shell a category, the bar legible, and the dock a real dock

Desktop & Dock becomes Shell — Bar, Dock, Control Center, Tiling,
Workspaces — the home for everything Quickshell draws. The settings-
management cluster moves to System as Sync & Backup, Appearance's
Shell tab dissolves, and 24-hour time finally lives on Date & Time,
which always owned it.

The bar gets what it never had: a way to survive the wallpaper. A
second neutral text family (follow theme, or forced light or dark),
a one-layer shadow under every glyph, and a gradient scrim for
wallpapers nothing else survives — all off by default, pixel-identical
until asked. Widgets earn toggles (weather, media, clipboard, calendar
countdown), the vitals cluster stops leaving a dead pill behind, and
Control Center's sections learn to step aside.

The dock graduates from MVP: a context menu with window rows, pin,
unpin, quit and new-window; scroll an icon to cycle its windows; drag
to reorder on the dock itself; hover previews with one-shot captures;
and "Add App to Dock" in the launcher. Three real bugs died en route —
menus that slid away with the autohide, a readonly-property crash on
every menu open, and a drag that drifted half a slot per icon on side
docks. The pinned-apps editor in Settings becomes a drag strip.

166 contracts; the full suite is green except two live display and
switcher tests that cannot run behind a locked session — re-verified
on unlock.

Claude-Session: https://claude.ai/code/session_01Ms2FbjQy31TVf3CEvQhGM8

config/dot/quickshell/modules/settings/SettingsShell.qml

@@ -166,7 +166,12 @@ Rectangle {
             case "connectivity": return connectivityPage;
             case "my-home": return myHomePage;
             case "phone": return phonePage;
-            case "desktop": return desktopPage;
+            case "bar": return barPage;
+            case "dock": return dockPage;
+            case "control-center": return controlCenterPage;
+            case "tiling": return tilingPage;
+            case "workspaces": return workspacesPage;
+            case "sync": return syncPage;
             case "sound": return soundPage;
             case "gaming": return gamingPage;
             case "notifications": return notificationsPage;
@@ -246,7 +251,12 @@ Rectangle {
     Component { id: connectivityPage; ConnectivityPage {} }
     Component { id: myHomePage; MyHomePage {} }
     Component { id: phonePage; PhonePage {} }
-    Component { id: desktopPage; DesktopPage {} }
+    Component { id: barPage; BarPage {} }
+    Component { id: dockPage; DockPage {} }
+    Component { id: controlCenterPage; ControlCenterPage {} }
+    Component { id: tilingPage; TilingPage {} }
+    Component { id: workspacesPage; WorkspacesPage {} }
+    Component { id: syncPage; SyncPage {} }
     Component { id: soundPage; SoundPage {} }
     Component { id: gamingPage; GamingPage {} }
     Component { id: notificationsPage; NotificationsPage {} }