quickshell: replace macOS-style shell with standalone overview module

Swap the illogical-impulse-derived components for the upstream
quickshell-overview standalone module, update Hyprland keybinds
(Super+Tab overview, rofi launcher), refresh foot colors and
starship theme, and adjust related host/module wiring.

home/hypr/quickshell.nix

@@ -8,16 +8,12 @@ in
 {
   home.packages = with pkgs; [
     quickshellPkg
-    brightnessctl
-    pamixer
-    playerctl
-    libnotify
-    grim
-    slurp
-    wl-clipboard
+    qt6.qtwayland
   ];
 
-  # Link Quickshell configuration into ~/.config/quickshell
+  # Quickshell overview module for Hyprland (Super+Tab workspace overview).
+  # Vendored from: https://github.com/Shanu-Kumawat/quickshell-overview
+  # Placed at the quickshell config root so a bare `qs` finds shell.qml.
   xdg.configFile."quickshell" = {
     source = ./quickshell;
     recursive = true;