refactor(home-manager): use flake-parts module

This is only available in the unstable HM branch, so we are stuck with
the non flake-parts version

flake-modules/default.nix

@@ -10,6 +10,7 @@ in
     ./docs.nix
     ./example-vm.nix
     ./nixos-modules.nix
+    ./home-modules.nix
     ./nixvim-modules.nix
     ./overlays.nix
     ./scripts.nix

flake-modules/home-modules.nix

@@ -0,0 +1,34 @@
+{ self, inputs, ... }:
+let
+  modules = ../modules;
+in
+{
+  # FIXME(25.05): this version of HM should have the flake module
+  # imports = [ inputs.home-manager.flakeModules.home-manager ];
+
+  flake.homeModules =
+    let
+      defaultModules = [
+        inputs.nixvim.homeManagerModules.nixvim
+        self.nixvimModules.homeManager
+        (modules + "/hm")
+      ];
+      nixos = {
+        imports = defaultModules;
+      };
+      standalone = {
+        imports = defaultModules ++ [
+          inputs.stylix.homeManagerModules.stilyx
+          (
+            { config, ... }:
+            {
+              stylix.image = config.jhome.sway.background;
+            }
+          )
+        ];
+      };
+    in
+    {
+      inherit standalone nixos;
+    };
+}

flake-modules/nixos-modules.nix

@@ -8,33 +8,7 @@ let
   modules = ../modules;
 in
 {
-  flake = {
-    homeManagerModules =
-      let
-        defaultModules = [
-          inputs.nixvim.homeManagerModules.nixvim
-          self.nixvimModules.homeManager
-          (modules + "/hm")
-        ];
-        nixos = {
-          imports = defaultModules;
-        };
-        standalone = {
-          imports = defaultModules ++ [
-            inputs.stylix.homeManagerModules.stilyx
-            (
-              { config, ... }:
-              {
-                stylix.image = config.jhome.sway.background;
-              }
-            )
-          ];
-        };
-      in
-      {
-        inherit standalone nixos;
-      };
-    nixosModules =
+  flake.nixosModules =
     let
       nixosModule = {
         imports = [
@@ -45,7 +19,7 @@ in
         home-manager = {
           useGlobalPkgs = true;
           useUserPackages = true;
-            sharedModules = [ self.homeManagerModules.nixos ];
+          sharedModules = [ self.homeModules.nixos ];
         };
         # Pin nixpkgs
         nix.registry.nixpkgs.flake = inputs.nixpkgs;
@@ -66,5 +40,4 @@ in
       inherit nixosModule;
     }
     // machineModules;
-  };
 }