Add linting, formatting, and CI with fixes for all warnings

Infrastructure:
- Add deadnix, nixfmt, and statix to flake inputs
- Add formatter output to flake for nix fmt support
- Add deadnix, nixfmt, statix to Home Manager packages
- Add GitHub Actions workflow for CI validation
- Add .pre-commit-config.yaml with hooks for nixfmt, deadnix, and statix
- Support x86_64-darwin in formatter

Statix fixes (W10/W20 warnings):
- Remove unused lambda argument from nixpkgs-settings.nix
- Merge repeated keys in hardware-configuration.nix files (boot.initrd, boot, fileSystems)
- Merge repeated keys in nixnuc/default.nix (services, virtualisation)
- Merge repeated keys in rainbow-planet/default.nix (desktopManager)
- Merge repeated keys in home/general/default.nix (home)

Deadnix fixes (unused declarations):
- Remove unused pkgs/lib/username/http_port arguments from various files
- Fix unused final parameter in overlay functions (final -> _final)

CI/pre-commit fixes:
- Fix pre-commit statix config: add pass_filenames: false
- Fix CI workflow: use nix run nixpkgs# prefix and --ci flag for nixfmt

modules/shared/nixos/flatpaks.nix

@@ -1,5 +1,4 @@
-
-{ ... }: {
+{
   services = {
     flatpak = {
       enable = true;

modules/shared/nixos/internationalisation.nix

@@ -1,4 +1,4 @@
-{ ... }: {
+{
   # Select internationalisation properties.
   i18n = {
     defaultLocale = "en_US.UTF-8";
@@ -14,4 +14,4 @@
       LC_TIME = "en_US.UTF-8";
     };
   };
-}
+}

modules/shared/nixos/lets-encrypt.nix

@@ -1,4 +1,5 @@
-{ config, username, ... }: {
+{ config, username, ... }:
+{
 
   ##########################################################################
   #                                                                        #
@@ -10,7 +11,9 @@
     acceptTerms = true;
     defaults = {
       email = "lets-encrypt@technicalissues.us";
-      credentialFiles = { "GANDIV5_PERSONAL_ACCESS_TOKEN_FILE" = "${config.sops.secrets.gandi_dns_pat.path}"; };
+      credentialFiles = {
+        "GANDIV5_PERSONAL_ACCESS_TOKEN_FILE" = "${config.sops.secrets.gandi_dns_pat.path}";
+      };
       dnsProvider = "gandiv5";
       dnsResolver = "ns1.gandi.net";
       # uncomment below for testing

modules/shared/nixos/nixroutes.nix

@@ -1,7 +1,7 @@
-{ config, lib, ... }:
+{ config, ... }:
 let
-  hostName = config.networking.hostName;
-in {
-  programs.zsh.shellAliases.nixroutes =
-    "cd ~/repos/dots && echo '=== Current Routes ===' && ip route show && ip -6 route show && echo '' && echo '=== New Build Routes ===' && nix eval --json '.#nixosConfigurations.${hostName}.config.systemd.network.networks.\"10-wan\".routes'";
+  inherit (config.networking) hostName;
+in
+{
+  programs.zsh.shellAliases.nixroutes = "cd ~/repos/dots && echo '=== Current Routes ===' && ip route show && ip -6 route show && echo '' && echo '=== New Build Routes ===' && nix eval --json '.#nixosConfigurations.${hostName}.config.systemd.network.networks.\"10-wan\".routes'";
 }

modules/shared/nixos/restic.nix

@@ -1,4 +1,5 @@
-{ config, pkgs, ... }: {
+{ config, pkgs, ... }:
+{
   environment.systemPackages = with pkgs; [
     restic
   ];
@@ -29,4 +30,3 @@
     };
   };
 }
-

modules/shared/nixos/ripping.nix

@@ -1,4 +1,5 @@
-{ pkgs, ... }: {
+{ pkgs, ... }:
+{
   # Be sure this is added if on NixOS
   # boot.kernelModules = [ "sg" ];
 
@@ -20,4 +21,3 @@
     mkvtoolnix-cli
   ];
 }
-