libkookie: dpi: add global dpi setting and wrap dino to use it

infra/libkookie/configuration/workstation/chat/default.nix

@@ -1,12 +1,24 @@
 { config, pkgs, ... }:
 
+let dpi = config.libkookie.ui.dpi;
+in
 {
+  imports = [ <modules/workstation/ui/dpi> ];
+
+  # TODO: set this somewhere else?
+  libkookie.ui.dpi = 1.2;
+  
   home.packages = with pkgs;
-    [
-      dino
-      quasselClient
-      element-desktop
-      signal-desktop
-      tdesktop
-    ];
+    let
+      dino2 = (writeShellScriptBin "dino" ''
+        GDK_DPI_SCALE=${builtins.toString dpi} ${dino}/bin/dino
+      '');
+    in
+      [
+        dino2
+        quasselClient
+        element-desktop
+        signal-desktop
+        tdesktop
+      ];
 }

infra/libkookie/modules/workstation/ui/dpi/default.nix

@@ -0,0 +1,16 @@
+{ config, lib, ... }:
+
+with lib;
+{
+  options.libkookie.ui.dpi = mkOption {
+    type = types.float;
+    default = 1.0;
+    description = ''
+      Override the default DPI scale for text on a system.  By default
+      this value is set to 1.0, meaning that an application _or_ a
+      display manager will set the font size for you.  By overriding
+      this setting it is possible to increase text size that is too
+      small by default.
+    '';
+  };
+}