Add ZFS support to sleeper-service

- Replace ext4 with ZFS pool 'filepool' for enhanced data integrity
- Add ZFS auto-scrub and TRIM services for file server
- Configure proper ZFS datasets: root, nix, var, storage
- Add networking hostId (a1b2c3d4) required for ZFS
- Update NFS and Transmission to use ZFS mount points
- Change file ownership to 'sma' user for server configuration
- Add comprehensive ZFS setup documentation

Ready for deployment with proper file server storage backend.

machines/sleeper-service/configuration.nix

@@ -14,14 +14,21 @@
     ../../modules/users/sma.nix
   ];
 
-  # Boot configuration
+  # Boot configuration with ZFS support
   boot.loader.grub = {
     enable = true;
+    zfsSupport = true;
     efiSupport = true;
     efiInstallAsRemovable = true;
     devices = [ "nodev" ];
   };
 
+  # ZFS services for file server
+  services.zfs = {
+    autoScrub.enable = true;
+    trim.enable = true;
+  };
+
   # Time and locale
   time.timeZone = "Europe/Oslo";
   i18n.defaultLocale = "en_US.UTF-8";