style(flake)!: manually import lib flake module

- Also make `lib` an `internal` option
- Unify let blocks and move them under `imports`
  (makes it clear where `config.lib` comes from)
- Fix a minor typo

modules/flake/configurations/default-generators.nix

@@ -5,9 +5,9 @@ let
     and
     hasFiles
     hasDirectories
-    configuration-type-to-outputs-modules;
-in
-let
+    configuration-type-to-outputs-modules
+    ;
+
   # `pkgs` with flake's overlays
   # NOTE: done here to avoid infinite recursion
   pkgs' = system:

modules/flake/configurations/default.nix

@@ -1,21 +1,19 @@
 { lib, config, self, inputs, withSystem, ... }:
 
-let
-  inherit (config.lib)
-    and
-    hasFiles
-    hasDirectories
-    recurseDir
-    kebabToCamel
-    configuration-type-to-outputs-modules;
-in
 {
   imports = [
+    ../lib
     ./default-generators.nix
   ];
 
   options = let
-    inherit (lib) types;
+    inherit (lib)
+      types
+      ;
+    inherit (config.lib)
+      recurseDir
+      kebabToCamel
+      ;
   in {
     auto.configurations = lib.mkOption {
       description = ''