Simplified input argument structures across multiple Nix modules by removing unnecessary bindings and standardizing formats. Enabled `system.primaryUser` setting and updated PAM configuration for sudo touch ID authentication. Removed deprecated or unused configurations, including user fields in metacfg and outdated options in some modules.
Moved default SSH keys to a shared `common.nix` module for better reusability and maintainability. Updated references in both NixOS and Darwin user modules to use the centralized keys. This reduces redundancy and improves consistency across modules.
Changed the neovim-flake URL to the new repository and updated its version from v0.5 to v0.6. This ensures we are using the latest configurations and features from the renamed repository.
