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/WallpaperPicker.qml

@@ -36,7 +36,13 @@ Item {
 
     // Videos join the grid only in single mode — slideshow and per-display
     // are hyprpaper's modes and stills-only.
-    readonly property var catalog: root.mode === "single"
+    // The test seam: a harness that supplies its own stills sets this false,
+    // and the picker then never touches the VideoWallpaper singleton at all —
+    // merely instantiating it would fire its startup restore inside the
+    // harness and play the machine's real wallpaper in a test instance.
+    property bool videoAware: true
+
+    readonly property var catalog: root.mode === "single" && root.videoAware
         ? Wallpaper.available.concat(VideoWallpaper.candidates)
         : Wallpaper.available
 
@@ -50,7 +56,7 @@ Item {
     readonly property real cellWidth: columns > 0 ? (width - (columns - 1) * 10) / columns : 160
 
     function isCurrent(path: string): bool {
-        if (VideoWallpaper.active)
+        if (root.videoAware && VideoWallpaper.active)
             return VideoWallpaper.path === path;
         return root.activeByOutput[root.selectedOutput] === path;
     }
@@ -88,7 +94,7 @@ Item {
                 required property var modelData
 
                 readonly property bool current: root.isCurrent(tile.modelData)
-                readonly property bool video: VideoWallpaper.isVideo(tile.modelData)
+                readonly property bool video: root.videoAware && VideoWallpaper.isVideo(tile.modelData)
                 readonly property bool member: root.mode === "slideshow" && root.selected(tile.modelData)
 
                 width: root.cellWidth