Enable Bitwarden CLI and keybind cheatsheet

Add bitwarden-cli, xdg-utils and gcc to essentials. Configure the
noctalia Bitwarden plugin with custom server and generation options.
Enable the keybind‑cheatsheet plugin and bind it to Super+Shift+K.
Replace several widget displays with gauge visualizations and add a
keybinds widget to the bar. Remove obsolete Bitwarden desktop toggles
from host modules.

modules/core/packages/packages.nix

@@ -14,7 +14,6 @@
   };
 
   packages = with pkgs; {
-    bitwarden = bitwarden-desktop;
     eddieAirVPN = eddie;
     gnomeCalculator = gnome-calculator;
     gedit = gedit;