feat(nix): use lix-module

Initially using Lix 2.93.2 from lix-module to fix critical regression.
Will later switch to Lix from nixpkgs to benefit from the cache.

flake.lock

@@ -250,6 +250,21 @@
         "type": "github"
       }
     },
+    "flakey-profile": {
+      "locked": {
+        "lastModified": 1712898590,
+        "narHash": "sha256-FhGIEU93VHAChKEXx905TSiPZKga69bWl1VB37FK//I=",
+        "owner": "lf-",
+        "repo": "flakey-profile",
+        "rev": "243c903fd8eadc0f63d205665a92d4df91d42d9d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "lf-",
+        "repo": "flakey-profile",
+        "type": "github"
+      }
+    },
     "gitignore": {
       "inputs": {
         "nixpkgs": [
@@ -313,6 +328,43 @@
         "type": "github"
       }
     },
+    "lix": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1751235704,
+        "narHash": "sha256-J4ycLoXHPsoBoQtEXFCelL4xlq5pT8U9tNWNKm43+YI=",
+        "rev": "1d7368585eebaa2c4bdbcb88fe600cfb2239b2c6",
+        "type": "tarball",
+        "url": "https://git.lix.systems/api/v1/repos/lix-project/lix/archive/1d7368585eebaa2c4bdbcb88fe600cfb2239b2c6.tar.gz?rev=1d7368585eebaa2c4bdbcb88fe600cfb2239b2c6"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://git.lix.systems/lix-project/lix/archive/release-2.93.tar.gz"
+      }
+    },
+    "lix-module": {
+      "inputs": {
+        "flake-utils": [
+          "flake-utils"
+        ],
+        "flakey-profile": "flakey-profile",
+        "lix": "lix",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1751240025,
+        "narHash": "sha256-SXUAlxpjPRkArRMHy5+Hdi+PiC+ND9yzzIjiaHmTvQU=",
+        "rev": "8b1094356f4723d6e89d3f8a95b333ee16d9ab02",
+        "type": "tarball",
+        "url": "https://git.lix.systems/api/v1/repos/lix-project/nixos-module/archive/8b1094356f4723d6e89d3f8a95b333ee16d9ab02.tar.gz?rev=8b1094356f4723d6e89d3f8a95b333ee16d9ab02"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://git.lix.systems/lix-project/nixos-module/archive/2.93.2-1.tar.gz"
+      }
+    },
     "matrix-appservices": {
       "inputs": {
         "devshell": "devshell",
@@ -468,6 +520,7 @@
         "flake-parts": "flake-parts",
         "flake-utils": "flake-utils",
         "home-manager": "home-manager_2",
+        "lix-module": "lix-module",
         "matrix-appservices": "matrix-appservices",
         "nixos-hardware": "nixos-hardware",
         "nixpkgs": "nixpkgs",

flake.nix

@@ -19,6 +19,12 @@ rec {
 
     nixos-hardware.url = "github:NixOS/nixos-hardware";
 
+    lix-module = {
+      url = "https://git.lix.systems/lix-project/nixos-module/archive/2.93.2-1.tar.gz";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.flake-utils.follows = "flake-utils";
+    };
+
     disko = {
       url = "github:nix-community/disko/latest";
       inputs.nixpkgs.follows = "nixpkgs";

system/nix.nix

@@ -10,9 +10,13 @@ let
   inherit (inputs.self.outputs) nixConfig;
 in
 {
-  nixpkgs.config.allowUnfree = true;
+  imports = [
+    # TODO switch to lixFromNixpkgs once 2.93.2 is available
+    inputs.lix-module.nixosModules.default
+    # inputs.lix-module.nixosModules.lixFromNixpkgs
+  ];
 
-  nix.package = pkgs.lix;
+  nixpkgs.config.allowUnfree = true;
 
   nix.gc = {
     automatic = true;