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/home/linux/apps/tilix.nix

@@ -1,4 +1,6 @@
-{ lib, pkgs, ... }: with lib.hm.gvariant; {
+{ lib, pkgs, ... }:
+with lib.hm.gvariant;
+{
 
   dconf.settings = {
     "com/gexperts/Tilix/profiles/2b7c4080-0ddd-46c5-8f23-563fd3ba789d" = {
@@ -10,7 +12,24 @@
       font = "Hack Nerd Font Mono 12";
       foreground-color = "#F8F8F2";
       highlight-colors-set = false;
-      palette = [ "#272822" "#F92672" "#A6E22E" "#F4BF75" "#66D9EF" "#AE81FF" "#A1EFE4" "#F8F8F2" "#75715E" "#F92672" "#A6E22E" "#F4BF75" "#66D9EF" "#AE81FF" "#A1EFE4" "#F9F8F5" ];
+      palette = [
+        "#272822"
+        "#F92672"
+        "#A6E22E"
+        "#F4BF75"
+        "#66D9EF"
+        "#AE81FF"
+        "#A1EFE4"
+        "#F8F8F2"
+        "#75715E"
+        "#F92672"
+        "#A6E22E"
+        "#F4BF75"
+        "#66D9EF"
+        "#AE81FF"
+        "#A1EFE4"
+        "#F9F8F5"
+      ];
       use-system-font = false;
       use-theme-colors = false;
       visible-name = "Default";
@@ -20,11 +39,13 @@
 
   home.file = {
     ".config/tilix/schemes/Beanbag-Mathias.json".source = ../../../files/tilix/Beanbag-Mathias.json;
-    ".config/tilix/schemes/Catppuccin-Frappe.json".source = (pkgs.fetchFromGitHub {
-      owner = "catppuccin";
-      repo = "tilix";
-      rev = "3fd05e03419321f2f2a6aad6da733b28be1765ef";
-      hash = "sha256-SI7QxQ+WBHzeuXbTye+s8pi4tDVZOV4Aa33mRYO276k=";
-    } + "/src/Catppuccin-Frappe.json");
+    ".config/tilix/schemes/Catppuccin-Frappe.json".source =
+      pkgs.fetchFromGitHub {
+        owner = "catppuccin";
+        repo = "tilix";
+        rev = "3fd05e03419321f2f2a6aad6da733b28be1765ef";
+        hash = "sha256-SI7QxQ+WBHzeuXbTye+s8pi4tDVZOV4Aa33mRYO276k=";
+      }
+      + "/src/Catppuccin-Frappe.json";
   };
-}
+}