feat(dotfiles): migrate flake scaffolding

src/dotfiles/default.nix

@@ -0,0 +1,54 @@
+{
+  lib,
+  inputs,
+  self,
+  root,
+}:
+let
+  util = import ./util.nix { inherit lib; };
+
+  registry = import ./registry.nix {
+    inherit lib;
+    hosts = self.nixosConfigurations;
+    root = root + "/registry";
+  };
+
+  modules = import ./modules.nix {
+    inherit util;
+    root = root + "/modules";
+  };
+
+  guestModules = import ./guests.nix {
+    inherit
+      inputs
+      lib
+      registry
+      specialArgs
+      util
+      ;
+    repositoryModules = modules;
+    root = root + "/guests";
+  };
+
+  specialArgs = {
+    inherit
+      inputs
+      self
+      util
+      ;
+    registry = registry.collected;
+  };
+in
+{
+  nixosConfigurations = import ./hosts.nix {
+    inherit
+      inputs
+      lib
+      specialArgs
+      guestModules
+      ;
+    registryModule = registry.module;
+    repositoryModules = modules;
+    root = root + "/hosts";
+  };
+}