remove duplicates already provided by niphas

- Delete configs/bash.nix (identical to niphas, was dead code)
- Delete configs/direnv.nix (dead code, niphas provides direnv)
- Delete packages/vimv.nix (identical to niphas)
- Remove vimv from overlay and packages output
- Alias niveum-terminal/browser/filemanager to niphas equivalents
- Remove 17 duplicate packages from configs/packages.nix
- Remove nil from configs/editor.nix (niphas provides it)
- Remove dead dmenu packageOverride from configs/default.nix

configs/default.nix

@@ -16,9 +16,6 @@ in
       nixpkgs = {
         config = {
           allowUnfree = true;
-          packageOverrides = pkgs: {
-            dmenu = pkgs.writers.writeDashBin "dmenu" ''exec ${pkgs.rofi}/bin/rofi -dmenu "$@"'';
-          };
           permittedInsecurePackages = [
           ];
         };