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/Bar.qml

@@ -16,6 +16,7 @@
 import Quickshell
 import Quickshell.Wayland
 import QtQuick
+import QtQuick.Effects
 import qs.config
 import qs.modules.clipboard
 import qs.modules.focus
@@ -62,13 +63,46 @@ PanelWindow {
         item: barContent
     }
 
+    // A scrim for wallpapers the bar cannot win against on tone alone. Drawn
+    // behind the content rows, fading out downward so the bar still has no
+    // hard edge of its own — the point is to darken what is under the text,
+    // not to give the bar a surface. Static: a gradient that never changes
+    // costs one paint, and this one has nothing to animate.
+    Rectangle {
+        anchors.fill: parent
+        visible: Settings.barBackdrop
+
+        gradient: Gradient {
+            GradientStop {
+                position: 0.0
+                color: Theme.alpha("#0c0e18", 0.55)
+            }
+            GradientStop {
+                position: 1.0
+                color: "transparent"
+            }
+        }
+    }
+
     Item {
         id: barContent
 
         anchors.fill: parent
 
+        // One shadow for the whole bar rather than one per widget: the content
+        // is flattened into a single layer and the halo is drawn under it, so
+        // every glyph and label picks it up and nothing has to opt in. Off by
+        // default — it only earns its layer on a busy wallpaper.
+        layer.enabled: Settings.barTextShadow
+        layer.effect: MultiEffect {
+            shadowEnabled: true
+            shadowColor: "#0a0c14"
+            shadowBlur: 0.6
+            shadowVerticalOffset: 1
+        }
+
         // ── Left ────────────────────────────────────────────────────────────
-            Row {
+        Row {
             anchors.left: parent.left
             anchors.verticalCenter: parent.verticalCenter
             spacing: Theme.itemSpacing