more refactors & outsource some things (#477)

* tree-wide: drop flake-parts

* drop nixinate

* justfile: cleanup

* drop treefmt-nix

* doc: update READMEs

* flake: cleanup

* seth: don't use `./.`

* modules/nixos,darwin: bundle all modules

They all depend on each other anyways so

* systems: manually import internal modules

* seth: use riff module from nix-exprs

* flake: back to flake-parts

* Revert "flake: back to flake-parts"

This reverts commit 35334882f7c0c23991a4efd65ea08b216006b2b0.

Saving the last commit so I can go back if I want

* flake: use lib.const

this looks better...right?

* flake: declare systems like a normal person

4 files changed, 79 insertions, 5 deletions

diff --git a/lib/README.md b/lib/README.md
index 97814c5..ad2d3ae 100644
--- a/lib/README.md
+++ b/lib/README.md
@@ -1,5 +1,10 @@
 # ./lib/
 
+## builders.nix
+
+Light wrappers around functions like `nixosSystem` and
+`homeManagerConfiguration`
+
 ## nginx.nix
 
 Small helpers to avoid boilerplate in the `services.nginx` module
diff --git a/lib/builders.nix b/lib/builders.nix
new file mode 100644
index 0000000..3cedb59
--- /dev/null
+++ b/lib/builders.nix
@@ -0,0 +1,66 @@
+{
+  lib,
+  inputs,
+  self,
+  ...
+}:
+{
+  nixosSystem =
+    {
+      nixpkgs ? inputs.nixpkgs,
+      specialArgs ? { },
+      ...
+    }@args:
+    nixpkgs.lib.nixosSystem (
+      lib.removeAttrs args [ "nixpkgs" ]
+      // {
+        specialArgs = specialArgs // {
+          inherit inputs;
+        };
+      }
+    );
+
+  darwinSystem =
+    {
+      nix-darwin ? inputs.nix-darwin or inputs.darwin,
+      specialArgs ? { },
+      ...
+    }@args:
+    nix-darwin.lib.darwinSystem (
+      lib.removeAttrs args [ "nix-darwin" ]
+      // {
+        specialArgs = specialArgs // {
+          inherit inputs;
+        };
+      }
+    );
+
+  homeManagerConfiguration =
+    {
+      extraSpecialArgs ? { },
+      ...
+    }@args:
+    inputs.home-manager.lib.homeManagerConfiguration (
+      args
+      // {
+        extraSpecialArgs = extraSpecialArgs // {
+          inherit inputs;
+        };
+      }
+    );
+
+  mkModule =
+    {
+      name,
+      type,
+      imports,
+    }@args:
+    {
+      _file = "${self.outPath}/flake.nix#${type}Modules.${name}";
+      inherit imports;
+    }
+    // lib.removeAttrs args [
+      "name"
+      "type"
+    ];
+}
diff --git a/lib/default.nix b/lib/default.nix
index df8d9fb..96d0a9f 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -1,9 +1,11 @@
 {
   lib,
+  inputs,
+  self,
   ...
 }:
-{
-  flake.lib = {
-    nginx = import ./nginx.nix lib;
-  };
+
+lib.mapAttrs (_: file: import file { inherit lib inputs self; }) {
+  builders = ./builders.nix;
+  nginx = ./nginx.nix;
 }
diff --git a/lib/nginx.nix b/lib/nginx.nix
index c2c99fb..80eb6ad 100644
--- a/lib/nginx.nix
+++ b/lib/nginx.nix
@@ -1,4 +1,5 @@
-lib: {
+{ lib, ... }:
+{
   /**
     Create an NGINX virtualHost submodule proxying a local port