feat: fixed more missing datasets

configurations/nixos/emergent/legacy-storage.nix

@@ -0,0 +1,51 @@
+# Legacy storage configuration for emergent
+# This file manually defines ZFS datasets matching the existing on-disk layout
+# to allow incremental migration to the new storage module (generateBase = true).
+#
+# Current on-disk dataset layout:
+#   rpool/local/                    - parent (canmount=off)
+#   rpool/local/system/nix          - nix store
+#   rpool/local/system/root         - root filesystem
+#
+# Migration plan:
+#   Phase 1: Rename datasets on disk (boot from live USB)
+#     zfs rename -p rpool/local/system/nix rpool/persist/local/nix
+#     zfs rename rpool/local rpool/persist/local
+#     # This moves: local/system/root -> persist/local/root (need to rename after)
+#     # Actually, since local/system/root needs to become persist/local/root:
+#     zfs rename rpool/persist/local/system/root rpool/persist/local/root
+#     zfs destroy rpool/persist/local/system  # now empty
+#     # Recreate blank snapshot:
+#     zfs destroy rpool/persist/local/root@blank
+#     zfs snapshot rpool/persist/local/root@blank
+#
+#   Phase 2: Delete this file, remove its import from default.nix, rebuild.
+{...}: {
+  # Disable automatic base dataset generation so we can define them manually
+  storage.generateBase = false;
+
+  # Manually define ZFS datasets matching the existing on-disk layout
+  storage.zfs.datasets = {
+    "local" = {
+      type = "zfs_fs";
+      mount = null;
+    };
+    "local/system/nix" = {
+      type = "zfs_fs";
+      mount = "/nix";
+      atime = "off";
+      relatime = "off";
+      snapshot = {
+        autoSnapshot = false;
+      };
+    };
+    "local/system/root" = {
+      type = "zfs_fs";
+      mount = "/";
+      snapshot = {
+        blankSnapshot = true;
+        autoSnapshot = true;
+      };
+    };
+  };
+}