Harden server and add Nix-native CI + self-hosted Gitea Actions

- caddy: security headers (X-Content-Type-Options/X-XSS-Protection/
  X-Frame-Options) on all vhosts + baseline CSP; strip SnappyMail
  upstream copies via header_down on mail.severijnse.eu
- tlsa-updater: compute TLSA 3 1 1 from cert SPKI (SHA-256), sync
  _25/_465/_993, fail-safe placeholders; coredns zone updated
- pre-commit: wire cachix/git-hooks.nix (alejandra, statix, actionlint,
  ...); CI pre-commit job over x86_64 + aarch64 matrix
- gitea: enable Gitea Actions + self-hosted runner (native:host,
  aarch64 via binfmt); add .gitea/workflows/ci.yml and local hook
- fix statix warnings (merge repeated systemd/database/configFile keys,
  inherit, bool-compare guards); add missing trailing newlines

home/editors/nvim/default.nix

@@ -1,5 +1,4 @@
 {
-  config,
   lib,
   pkgs,
   ...

home/editors/zed/default.nix

@@ -1,5 +1,4 @@
 {
-  config,
   lib,
   pkgs,
   ...

home/packages/android.nix

@@ -1,8 +1,4 @@
-{
-  inputs,
-  pkgs,
-  ...
-}: let
+{pkgs, ...}: let
   kotlin-lsp = pkgs.runCommand "kotlin-lsp" {} ''
     mkdir -p $out/bin
     ln -s ${pkgs.kotlin-language-server}/bin/kotlin-language-server $out/bin/kotlin-lsp

home/packages/packages.nix

@@ -1,8 +1,4 @@
-{
-  inputs,
-  pkgs,
-  ...
-}: {
+{pkgs, ...}: {
   users.users.someone.packages = with pkgs; [
     # screenshot
     grim

home/packages/wayland/niri/_binds.nix

@@ -1,4 +1,4 @@
-{pkgs}: {
+{}: {
   "XF86AudioPlay" = {
     _props.allow-when-locked = true;
     spawn._args = ["playerctl" "play-pause"];

home/services/wayland/ashell.nix

@@ -1,9 +1,4 @@
-{
-  config,
-  pkgs,
-  lib,
-  ...
-}: {
+{pkgs, ...}: {
   users.users.someone.packages = [pkgs.ashell];
 
   xdg.configFile."ashell/config.toml".text = ''

home/services/wayland/mako.nix

@@ -1,9 +1,4 @@
-{
-  config,
-  pkgs,
-  lib,
-  ...
-}: {
+{pkgs, ...}: {
   users.users.someone.packages = [pkgs.mako];
 
   xdg.configFile."mako/config".text = ''

home/services/wayland/walker.nix

@@ -1,9 +1,4 @@
-{
-  config,
-  pkgs,
-  lib,
-  ...
-}: {
+{pkgs, ...}: {
   users.users.someone.packages = [pkgs.walker pkgs.elephant];
 
   xdg.configFile."walker/config.toml".text = ''

home/terminal/emulators/alacritty.nix

@@ -1,8 +1,4 @@
-{
-  pkgs,
-  lib,
-  ...
-}: let
+{pkgs, ...}: let
   alacritty-wrapped = pkgs.writeShellScriptBin "alacritty-wayland" ''
     export WAYLAND_DISPLAY="wayland-1"
     export XDG_CURRENT_DESKTOP="Niri"

home/terminal/software/ssh.nix

@@ -2,9 +2,7 @@
   config,
   pkgs,
   ...
-}: let
-  sshConfigFile = "ssh/config";
-in {
+}: {
   users.users.someone.packages = with pkgs; [
     openssh
   ];

home/terminal/software/tui.nix

@@ -1,8 +1,4 @@
-{
-  inputs,
-  pkgs,
-  ...
-}: {
+{pkgs, ...}: {
   users.users.someone.packages = with pkgs; [
     # archives
     zip

home/xdg-compat.nix

@@ -159,7 +159,7 @@ in {
       ${lib.concatStringsSep "\n" (
         lib.flatten (
           lib.mapAttrsToList (
-            user: userCfg:
+            _user: userCfg:
               (lib.mapAttrsToList (mkLinkScript cfg.configHome) userCfg.configFiles)
               ++ (lib.mapAttrsToList (mkLinkScript cfg.cacheHome) userCfg.cacheFiles)
               ++ (lib.mapAttrsToList (mkLinkScript cfg.dataHome) userCfg.dataFiles)