Add udev rule to make YubiKey CCID interface accessible to pcscd

nixos/modules/yubikey.nix

@@ -13,6 +13,13 @@
     libu2f-host
   ];
 
+  # Add udev rule for YubiKey CCID interface to be readable by pcscd
+  services.udev.extraRules = ''
+    # YubiKey FIDO+CCID (0x0406) - ensure CCID interface is accessible
+    SUBSYSTEM=="usb", ATTRS{idVendor}=="1050", ATTRS{idProduct}=="0406", MODE="0666"
+    SUBSYSTEM=="usb_device", ATTRS{idVendor}=="1050", ATTRS{idProduct}=="0406", MODE="0666"
+  '';
+
   # CCID driver for smartcard access (required for YubiKey CCID functionality)
   # Set up the PC/SC drivers directory with CCID driver bundle
   system.activationScripts.pcscdSetup = ''