desktop: autologin into Hyprland, Qt/KDE theming, dots fonts

Disable UWSM (black-screens under NVIDIA), autologin to the Hyprland
session, restore upstream qt platformTheme=kde + Darkly, and install the
fonts the end-4 dots actually reference (Google Sans Flex, Readex Pro,
Space Grotesk).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

modules/desktop.nix

@@ -1,8 +1,11 @@
-{ pkgs, ... }:
+{ inputs, pkgs, ... }:
 
 {
   # System-side requirements of illogical-flake (the HM module does the rest)
-  programs.hyprland.enable = true;
+  programs.hyprland = {
+    enable = true;
+    withUWSM = false; # UWSM session black-screens (NVIDIA env vars + non-UWSM-aware dots)
+  };
   services.geoclue2.enable = true; # QtPositioning — weather / night light widgets
 
   services.displayManager.sddm = {
@@ -10,8 +13,29 @@
     wayland.enable = true;
   };
 
+  # Boot straight into Hyprland; the illogical-impulse lock screen acts as the
+  # login page (lock.launchOnStartup in ~/.config/illogical-impulse/config.json)
+  services.displayManager.autoLogin = {
+    enable = true;
+    user = "zephrynis";
+  };
+  services.displayManager.defaultSession = "hyprland";
+
   xdg.portal.extraPortals = [ pkgs.xdg-desktop-portal-gtk ]; # file pickers etc.
 
+  # Qt app theming (Prism Launcher, protonup-qt, …), matching upstream Arch:
+  # the dots set QT_QPA_PLATFORMTHEME=kde and write wallpaper Material You
+  # colors + widgetStyle=Darkly into ~/.config/kdeglobals, assuming
+  # plasma-integration and Darkly are system-installed (like Bibata). The
+  # illogical-flake port overrides the platform theme to qt6ct in
+  # hypr/custom/env.lua — countered in home/zephrynis.nix. No qt.style here:
+  # QT_STYLE_OVERRIDE would beat kdeglobals' widgetStyle.
+  qt = {
+    enable = true;
+    platformTheme = "kde";
+  };
+  environment.systemPackages = [ pkgs.darkly ]; # Qt6 only; no qt5 variant in nixpkgs
+
   security.polkit.enable = true;
   programs.dconf.enable = true;
   services.gvfs.enable = true;
@@ -19,6 +43,16 @@
   services.upower.enable = true;
 
   fonts.packages = with pkgs; [
+    # Fonts the current dots actually use (config.json appearance.fonts):
+    # main/title/numbers = Google Sans Flex, reading = Readex Pro,
+    # expressive = Space Grotesk. Without these everything silently falls
+    # back to DejaVu Sans.
+    (runCommand "google-sans-flex-font" { } ''
+      install -Dm644 ${inputs.google-sans-flex}/*.ttf -t $out/share/fonts/truetype
+    '')
+    readexpro
+    (google-fonts.override { fonts = [ "SpaceGrotesk" ]; })
+
     # named by the illogical-flake README
     rubik
     nerd-fonts.ubuntu