Refactor: Simplify module structure and reorganize services

- Removed system/ directory, merged applications into users/geir.nix
- Simplified fonts.nix to bare minimum (users can add more)
- Moved transmission.nix to sleeper-service/services/ (machine-specific)
- Organized grey-area services into services/ directory
- Updated import paths and tested all configurations
- Added research documentation for deploy-rs and GNU Stow

machines/grey-area/hardware-configuration.nix

@@ -0,0 +1,40 @@
+# Do not modify this file!  It was generated by ‘nixos-generate-config’
+# and may be overwritten by future invocations.  Please make changes
+# to /etc/nixos/configuration.nix instead.
+{ config, lib, pkgs, modulesPath, ... }:
+
+{
+  imports =
+    [ (modulesPath + "/installer/scan/not-detected.nix")
+    ];
+
+  boot.initrd.availableKernelModules = [ "xhci_pci" "ehci_pci" "ahci" "usb_storage" "usbhid" "sd_mod" ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  fileSystems."/" =
+    { device = "/dev/disk/by-uuid/b101efbd-a6b3-494d-9c21-21187540dc8d";
+      fsType = "ext4";
+    };
+
+  fileSystems."/boot" =
+    { device = "/dev/disk/by-uuid/E251-F60A";
+      fsType = "vfat";
+    };
+  fileSystems."/mnt/remote/media" =
+    { device = "sleeper-service:/mnt/storage";
+      fsType = "nfs";
+    };
+  swapDevices = [ ];
+  # Enables DHCP on each ethernet and wireless interface. In case of scripted networking
+  # (the default) this is the recommended approach. When using systemd-networkd it's
+  # still possible to use this option, but it's recommended to use it in conjunction
+  # with explicit per-interface declarations with `networking.interfaces.<interface>.useDHCP`.
+  networking.useDHCP = lib.mkDefault true;
+  # networking.interfaces.enp1s0.useDHCP = lib.mkDefault true;
+  # networking.interfaces.enp8s0.useDHCP = lib.mkDefault true;
+
+  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+  hardware.cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
+}