refactor(flake): move shared utility functions

src/dotfiles/util.nix

@@ -1,25 +1,9 @@
 { lib }:
 let
-  collectNixFiles =
-    dir:
-    lib.flatten (
-      lib.mapAttrsToList (
-        name: type:
-        let
-          path = dir + "/${name}";
-        in
-        if type == "directory" then
-          collectNixFiles path
-        else if type == "regular" && lib.hasSuffix ".nix" name then
-          [ path ]
-        else
-          [ ]
-      ) (builtins.readDir dir)
-    );
+  flakeUtil = import ../flake/util.nix { inherit lib; };
 in
-{
-  inherit collectNixFiles;
-
+flakeUtil
+// {
   bridgeName = id: "br-vlan${toString id}";
 
   deriveMac =

src/flake/default.nix

@@ -6,7 +6,7 @@
   system,
 }:
 let
-  util = import ../dotfiles/util.nix { inherit lib; };
+  util = import ./util.nix { inherit lib; };
 
   dotfiles = import ../dotfiles {
     inherit

src/flake/util.nix

@@ -0,0 +1,22 @@
+{ lib }:
+let
+  collectNixFiles =
+    dir:
+    lib.flatten (
+      lib.mapAttrsToList (
+        name: type:
+        let
+          path = dir + "/${name}";
+        in
+        if type == "directory" then
+          collectNixFiles path
+        else if type == "regular" && lib.hasSuffix ".nix" name then
+          [ path ]
+        else
+          [ ]
+      ) (builtins.readDir dir)
+    );
+in
+{
+  inherit collectNixFiles;
+}