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/bar/StatusCluster.qml

@@ -77,10 +77,10 @@ Pill {
 
         color: {
             if (root.wiredDevice)
-                return Theme.fg;
+                return Theme.barFg;
             if (!root.wifiNetwork)
-                return Theme.fgMuted;
-            return Networking.connectivity === NetworkConnectivity.Full ? Theme.fg : Theme.warn;
+                return Theme.barFgMuted;
+            return Networking.connectivity === NetworkConnectivity.Full ? Theme.barFg : Theme.warn;
         }
     }
 
@@ -91,7 +91,7 @@ Pill {
         visible: KeyboardLayout.multiple
         anchors.verticalCenter: parent.verticalCenter
         text: KeyboardLayout.shortLabel
-        color: Theme.fg
+        color: Theme.barFg
         font.family: Theme.fontFamily
         font.pixelSize: Theme.fontSizeSmall
         font.weight: Font.Medium
@@ -117,7 +117,7 @@ Pill {
                 return "\u{F0580}";              // md-volume_medium
             return "\u{F057E}";                  // md-volume_high
         }
-        color: root.muted ? Theme.fgMuted : Theme.fg
+        color: root.muted ? Theme.barFgMuted : Theme.barFg
     }
 
     StatusGlyph {
@@ -125,7 +125,7 @@ Pill {
         // simply absent rather than shown crossed out.
         visible: root.bluetoothOn
         glyph: root.bluetoothConnected ? "\u{F00B1}" : "\u{F00AF}"   // md-bluetooth_connect / md-bluetooth
-        color: root.bluetoothConnected ? Theme.accent : Theme.fg
+        color: root.bluetoothConnected ? Theme.accent : Theme.barFg
     }
 
     StatusGlyph {
@@ -151,7 +151,7 @@ Pill {
         if (Battery.critical) return Theme.danger;
         if (Battery.low) return Theme.warn;
         if (Battery.charging) return Theme.ok;
-        return Theme.fg;
+        return Theme.barFg;
     }
 
     StatusGlyph {