gaming: udev rules for phantom controllers and WebHID configurators

Clear ID_INPUT_JOYSTICK on the Keychron keyboard (3434) and X3PRO mouse
receiver (3151) so Steam/games stop grabbing them as a phantom controller.
Also grant the active session uaccess to those devices' hidraw nodes via a
60-*.rules package file (must sort before systemd's 73-seat-late.rules) so
their browser-based WebHID configurators work.

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

modules/gaming.nix

@@ -29,4 +29,35 @@
     enable = true;
     packages = [ "io.mrarm.mcpelauncher" ];
   };
+
+  # Some devices expose a control interface that udev misdetects as a joystick,
+  # so Steam/games pick up a phantom controller and grab input. Clear
+  # ID_INPUT_JOYSTICK for them (extraRules → 99-local.rules is fine here, since
+  # this only rewrites a udev property later consumers read):
+  #   3434 = Keychron keyboard
+  #   3151 = "2.4G Wireless Mouse" (X3PRO) receiver
+  services.udev.extraRules = ''
+    SUBSYSTEM=="input", ATTRS{idVendor}=="3434", ENV{ID_INPUT_JOYSTICK}=""
+    SUBSYSTEM=="input", ATTRS{idVendor}=="3151", ENV{ID_INPUT_JOYSTICK}=""
+  '';
+
+  # Browser-based (WebHID) configurators need the logged-in user to have access
+  # to the device's raw HID nodes:
+  #   3434 = Keychron keyboard   (launcher.keychron.com)
+  #   3151 = X3PRO mouse         (its web editor)
+  # TAG+="uaccess" makes systemd-logind grant the active session an ACL — but
+  # that tag is CONSUMED by systemd's 73-seat-late.rules, so the rule must sort
+  # BEFORE it. services.udev.extraRules lands in 99-local.rules (too late), so
+  # ship this as a package-provided 60-*.rules file instead.
+  # (WebHID is Chromium-only — use Chrome, not Firefox.)
+  services.udev.packages = [
+    (pkgs.writeTextFile {
+      name = "hid-webconfig-uaccess";
+      destination = "/etc/udev/rules.d/60-hid-webconfig-uaccess.rules";
+      text = ''
+        KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{idVendor}=="3434", TAG+="uaccess"
+        KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{idVendor}=="3151", TAG+="uaccess"
+      '';
+    })
+  ];
 }