feat(attic): update storage config and refine system settings

- Switch disk device from `/dev/vda` to `/dev/sda` for compatibility.
- Add S3 storage configuration with bucket, region, and endpoint.
- Update system state version from `24.05` to `25.11`.
- Remove unused imports and clean up redundant attributes.

systems/x86_64-linux/attic/hardware-configuration.nix

@@ -0,0 +1,38 @@
+# 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 = [
+    ./disko.nix
+    (modulesPath + "/profiles/qemu-guest.nix")
+  ];
+  disko.devices.disk.main.device = "/dev/sda";
+
+  boot.initrd.availableKernelModules = [
+    "ahci"
+    "xhci_pci"
+    "virtio_pci"
+    "sr_mod"
+    "virtio_blk"
+  ];
+  boot.initrd.kernelModules = [ ];
+  boot.kernelModules = [ "kvm-intel" ];
+  boot.extraModulePackages = [ ];
+
+  # 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;
+
+  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+}