Revert "impermanence"

This reverts commit 9d0d0b10d1.

disk-config.nix

@@ -15,29 +15,17 @@
                 mountpoint = "/boot";
               };
             };
-            persistent = {
+            root = {
               size = "100%";
               content = {
                 type = "filesystem";
                 format = "f2fs";
-                mountpoint = "/persistent";
+                mountpoint = "/";
               };
             };
           };
         };
       };
     };
-    nodev = {
-      "/" = {
-        fsType = "tmpfs";
-        mountOptions = [
-          "defaults"
-          "size=2G"
-          "mode=755"
-        ];
-      };
-    };
   };
-
-  fileSystems."/persistent".neededForBoot = true;
 }