WIP: home: delta: use stand-alone configuration file

Ideally, I'd like for `delta` to just read a configuration file at
`$XDG_CONFIG_HOME/delta/config` by default, but upstream seems somewhat
reticent to the idea :-/.

TODO:
* `git.enable = false` would break the standalone configuration
* using a wrapper which sets `--config` might be better than includes

hosts/homes/ambroisie@mousqueton/default.nix

@@ -15,6 +15,9 @@
       # I use scripts that use the passthrough sequence often on this host
       enablePassthrough = true;
 
+      # Frequent reboots mean that session persistence can be handy
+      enableResurrect = true;
+
       terminalFeatures = {
         # HTerm uses `xterm-256color` as its `$TERM`, so use that here
         xterm-256color = { };

modules/home/packages/default.nix

@@ -1,6 +1,7 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, osConfig, ... }:
 let
   cfg = config.my.home.packages;
+  useGlobalPkgs = osConfig.home-manager.useGlobalPkgs or false;
 in
 {
   options.my.home.packages = with lib; {
@@ -29,7 +30,7 @@ in
       tree
     ] ++ cfg.additionalPackages);
 
-    nixpkgs.config = {
+    nixpkgs.config = lib.mkIf (!useGlobalPkgs) {
       inherit (cfg) allowAliases allowUnfree;
     };
   };

modules/home/pager/default.nix

@@ -16,7 +16,11 @@ in
       LESS = "-R -+X -c";
       # Better XDG compliance
       LESSHISTFILE = "${config.xdg.stateHome}/less/history";
-      LESSKEY = "${config.xdg.configHome}/less/lesskey";
     };
+
+    xdg.configFile."lesskey".text = ''
+      # Quit without clearing the screen on `Q`
+      Q toggle-option -!^Predraw-on-quit\nq
+    '';
   };
 }

modules/home/tmux/default.nix

@@ -20,6 +20,8 @@ in
 
     enablePassthrough = mkEnableOption "tmux DCS passthrough sequence";
 
+    enableResurrect = mkEnableOption "tmux-resurrect plugin";
+
     terminalFeatures = mkOption {
       type = with types; attrsOf (submodule {
         options = {
@@ -50,6 +52,7 @@ in
     mouse = false; # I dislike mouse support
     focusEvents = true; # Report focus events
     terminal = "tmux-256color"; # I want accurate termcap info
+    aggressiveResize = true; # Automatic resize when switching client size
 
     plugins = with pkgs.tmuxPlugins; [
       # Open high-lighted files in copy mode
@@ -79,6 +82,13 @@ in
           set -g status-right '#{prefix_highlight} %a %Y-%m-%d %H:%M'
         '';
       }
+      # Resurrect sessions
+      (lib.optionalAttrs cfg.enableResurrect {
+        plugin = resurrect;
+        extraConfig = ''
+          set -g @resurrect-dir '${config.xdg.stateHome}/tmux/resurrect'
+        '';
+      })
     ];
 
     extraConfig = ''