feat: ✨ add comprehensive ThinkPad T14 Intel Gen 6 hardware support

Add complete hardware profile for Lenovo ThinkPad T14 Intel Gen 6 with:
- Lunar Lake CPU architecture support
- Intel Arc graphics integration
- Kernel parameters for backlight and touchpad optimization
- Fingerprint reader support with PAM configuration guidance
- Disabled throttled service for modern Intel power management

Includes comprehensive documentation for fingerprint authentication
setup with warnings about potential login issues and proper PAM
configuration in host systems.

Signed-off-by: Dustin Krysak <[email protected]>

Author: bashfulrobot

lenovo/thinkpad/t14/intel/gen6/default.nix

@@ -17,4 +17,44 @@
 
   # Ensure modern kernel for full Lunar Lake support
   boot.kernelPackages = lib.mkIf (lib.versionOlder pkgs.linux.version "6.8") pkgs.linuxPackages_latest;
+
+  # TODO: Looking for feedback on these kernel parameters for T14 Gen 6
+  # Force use of the thinkpad_acpi driver for backlight control
+  # This allows the backlight save/load systemd service to work
+  boot.kernelParams = [
+    "acpi_backlight=native"
+    # TODO: Looking for feedback - touchpad fix needed for proper click registration on some T14 models
+    "psmouse.synaptics_intertouch=0"
+  ];
+
+  # TODO: Looking for feedback - modern Intel CPUs don't typically need throttled service
+  # which can interfere with newer power management on Lunar Lake
+  services.throttled.enable = lib.mkDefault false;
+
+  # Enable fingerprint reader support
+  # NOTE: PAM configuration should be done in host config to avoid login issues
+  # See: https://github.com/NixOS/nixpkgs/issues/171136
+  services.fprintd.enable = lib.mkDefault true;
+
+  # For complete fingerprint authentication in GNOME, add the following to your host config:
+  #
+  # security.pam.services = {
+  #   # Enable fingerprint authentication for sudo
+  #   sudo.fprintAuth = lib.mkDefault true;
+  #   
+  #   # Enable fingerprint authentication for su
+  #   su.fprintAuth = lib.mkDefault true;
+  #   
+  #   # Enable fingerprint authentication for screen unlock
+  #   xscreensaver.fprintAuth = lib.mkDefault true;
+  #   
+  #   # WARNING: login.fprintAuth may break GDM password authentication
+  #   # Only enable if you understand the risks:
+  #   # login.fprintAuth = lib.mkDefault true;
+  # };
+  #
+  # After configuration:
+  # 1. Rebuild your system
+  # 2. Enroll fingerprint: sudo fprintd-enroll $USER
+  # 3. Test sudo and screen unlock with fingerprint
 }