Fix nix flake check warnings and errors

- Move nextcloud-talk-desktop to x86_64-linux-only block (fixes aarch64 eval error)
- Remove duplicate deps from plasma-bigscreen (auto-injected by mkKdeDerivation)
- Replace nixfmt-rfc-style with nixfmt (deprecated alias)
- Set programs.git.signing.format = null (adopt new default)
- Add meta.description to all flake apps

home/roles/base/default.nix

@@ -60,6 +60,7 @@ in
 
     programs.git = {
       enable = true;
+      signing.format = null;
       settings = {
         user.name = "John Ogle";
         user.email = "john@ogle.fyi";

home/roles/emacs/default.nix

@@ -1,4 +1,9 @@
-{ config, lib, pkgs, ... }:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 
@@ -20,9 +25,10 @@ let
 
   # Default emacs configuration with vterm support
   defaultEmacsPackage =
-    if pkgs.stdenv.isDarwin
-    then pkgs.emacs-macport.pkgs.withPackages emacsPackages
-    else pkgs.emacs.pkgs.withPackages emacsPackages;
+    if pkgs.stdenv.isDarwin then
+      pkgs.emacs-macport.pkgs.withPackages emacsPackages
+    else
+      pkgs.emacs.pkgs.withPackages emacsPackages;
 
   # Path to doom config directory (relative to this file)
   doomConfigDir = ./doom;
@@ -56,8 +62,8 @@ in
         pkgs.nerd-fonts.fira-code
         pkgs.nerd-fonts.droid-sans-mono
         pkgs.nil # nix lsp language server
-        pkgs.nixfmt-rfc-style
-        (pkgs.ripgrep.override {withPCRE2 = true;})
+        pkgs.nixfmt
+        (pkgs.ripgrep.override { withPCRE2 = true; })
         pkgs.pipenv
         pkgs.poetry
         pkgs.python3
@@ -88,7 +94,7 @@ in
       };
 
       # TODO: Use mkOutOfStoreSymlink instead?
-      home.activation.doomConfig = lib.hm.dag.entryAfter ["writeBoundary"] ''
+      home.activation.doomConfig = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
         # Always remove and recreate the symlink to ensure it points to the source directory
         rm -rf "${config.xdg.configHome}/doom"
         ln -sf "${config.home.homeDirectory}/nixos-configs/home/roles/emacs/doom" "${config.xdg.configHome}/doom"