- Switch back to a reasonable home-manager.backupFileExtension
- Extract defaultApplications to its own file, fix default apps not being "sticky" by using the `.desktop` file alone (without absolute path).
- Run "fastfetch" by name in zsh.initExtra.
- Delete homeManagerConfigurations from flake.
- Delete laptop nixosConfiguration.
- Delete `home-manager/` and `nixos/` directories.
- Switch from one general "vars" attrset for variables to using built-for-purpose attrsets for variables, each declared where it makes most sense (e.g. the "sys" attrset will be used for system-specific attributes).
- Create `systems/` directory for root-level system configurations and `modules/` directory for re-usable config files.
- Consolidate most app and system configuration into the `desktop-environment.nix` and `terminal-environment.nix` files.
- Standardize all `.nix` files to nixos config nodes, as opposed to home-manager. May reverse this decision.
- Use `${sys.username}` for the username of the primary user of the system.
- Use `${usr.${sys.username}}` for attributes related to that user (e.g. realname, email).
