fix: aerospace more strict, system fix

modules/home/programs/neovim.nix

@@ -18,7 +18,6 @@
     extraPackages = with pkgs; [
       # LSP Servers
       lua-language-server
-      nil # Nix LSP
       pyright
       nodePackages.typescript-language-server
       mdx-language-server

modules/home/programs/nvim/lua/plugins/lsp.lua

@@ -53,11 +53,11 @@ return {
         },
       })
 
-      -- Nix
-      lspconfig.nil_ls.setup({
+      -- Nix (using nixd instead of nil to avoid nix 2.31.x test failures)
+      lspconfig.nixd.setup({
         capabilities = capabilities,
         settings = {
-          ["nil"] = {
+          nixd = {
             formatting = { command = { "nixfmt" } },
           },
         },