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/sgx-attic/atticd.nix

@@ -1,58 +0,0 @@
-{
-  pkgs,
-  lib,
-  config,
-  ...
-}:
-{
-  services.postgresql = {
-    enable = true;
-    ensureDatabases = [ "attic" ];
-    ensureUsers = [ { name = "atticd"; } ];
-  };
-
-  systemd.services.postgresql.postStart = lib.mkAfter ''
-    $PSQL -tAc 'ALTER DATABASE "attic" OWNER TO "atticd"'
-  '';
-
-  environment.systemPackages = with pkgs; [ attic-client ];
-  services.atticd = {
-    enable = true;
-
-    # Replace with absolute path to your credentials file
-    environmentFile = "/etc/atticd.env";
-
-    settings = {
-      api-endpoint = "https://attic.teepot.org/";
-
-      garbage-collection.default-retention-period = "3 months";
-
-      database.url = "postgresql:///attic?host=/run/postgresql";
-
-      listen = "[::]:8080";
-
-      # Data chunking
-      #
-      # Warning: If you change any of the values here, it will be
-      # difficult to reuse existing chunks for newly-uploaded NARs
-      # since the cutpoints will be different. As a result, the
-      # deduplication ratio will suffer for a while after the change.
-      chunking = {
-        # The minimum NAR size to trigger chunking
-        #
-        # If 0, chunking is disabled entirely for newly-uploaded NARs.
-        # If 1, all NARs are chunked.
-        nar-size-threshold = 64 * 1024; # 64 KiB
-
-        # The preferred minimum size of a chunk, in bytes
-        min-size = 16 * 1024; # 16 KiB
-
-        # The preferred average size of a chunk, in bytes
-        avg-size = 64 * 1024; # 64 KiB
-
-        # The preferred maximum size of a chunk, in bytes
-        max-size = 256 * 1024; # 256 KiB
-      };
-    };
-  };
-}