fix: ship a numbered udev rule file for vial since otherwise it gets overwritten by systemd's udev file

Reviewed-on: #69

hosts/argon/configuration.nix

@@ -26,6 +26,7 @@
     ../../modules/nixos/steam.nix
     ../../modules/nixos/thunar.nix
     ../../modules/nixos/users.nix
+    ../../modules/nixos/vial.nix
   ];
 
   # set hostname

hosts/neon/configuration.nix

@@ -22,6 +22,7 @@
     ../../modules/nixos/settings.nix
     ../../modules/nixos/steam.nix
     ../../modules/nixos/users.nix
+    ../../modules/nixos/vial.nix
   ];
 
   # set hostname

modules/nixos/packages.nix

@@ -35,6 +35,7 @@
     tree
     unzip
     usbutils
+    vial
     vim
     wget
     which

modules/nixos/vial.nix

@@ -0,0 +1,26 @@
+{ config, lib, pkgs, ... }:
+
+{
+  # Vial-capable keyboards (lily58 pro r2g) expose a second, non-keyboard raw
+  # HID interface that vial.rocks drives over WebHID. Its /dev/hidraw* node is
+  # root-only by default, so neither chromium nor the native app can open it.
+  #
+  # This has to ship as a numbered rules file rather than via
+  # services.udev.extraRules: extraRules lands in 99-local.rules, but the
+  # builtin that turns TAG+="uaccess" into an actual ACL is invoked from
+  # systemd's 73-seat-late.rules. A tag set at 99 is set too late to be seen,
+  # so the device ends up correctly tagged and still unreadable. 60- sorts
+  # safely ahead of 73.
+  services.udev.packages = [
+    (pkgs.writeTextFile {
+      name = "vial-udev-rules";
+      destination = "/lib/udev/rules.d/60-vial.rules";
+      # Vial firmware advertises itself through a magic USB serial, so this
+      # matches any vial board rather than just the lily58. uaccess hands the
+      # device to whoever owns the active seat, no group membership needed.
+      text = ''
+        KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{serial}=="*vial:f64c2b3c*", TAG+="uaccess"
+      '';
+    })
+  ];
+}