quickshell: force Papirus-Fred icon theme, qt5ct bypasses gsettings

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

settings/quickshell.nix

@@ -46,6 +46,11 @@ in
           ExecStart = "${pkgs.quickshell}/bin/qs";
           Restart = "always";
           RestartSec = 2;
+          # Stylix sets QT_QPA_PLATFORMTHEME=qt5ct system-wide, so Qt asks
+          # qt6ct for the icon theme and never sees the gsettings value.
+          # Quickshell honours this override; without it the Papirus-Fred →
+          # YAMIS Inherits chain is bypassed entirely.
+          Environment = [ "QS_ICON_THEME=Papirus-Fred" ];
         };
         Install.WantedBy = [ "hyprland-session.target" ];
       };