feat: grlx LSP server in Go

LSP server for grlx recipe files (.grlx) providing:

- Completion for ingredients, methods, properties, requisite types,
  and step ID references
- Diagnostics for unknown ingredients/methods, missing required
  properties, unknown properties, and invalid requisite types
- Hover documentation for all ingredients and methods with property
  tables
- Full schema for all 6 grlx ingredients (cmd, file, group, pkg,
  service, user) with accurate properties from the grlx source

flake.nix

@@ -0,0 +1,97 @@
+{
+  description = "A flake for grlx-nom, with Hercules CI support";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+    crane = {
+      url = "github:ipetkov/crane";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    flake-utils.url = "github:numtide/flake-utils";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+  };
+
+  outputs = inputs @ {
+    self,
+    flake-parts,
+    nixpkgs,
+    crane,
+    flake-utils,
+    ...
+  }:
+    flake-parts.lib.mkFlake {inherit inputs;} {
+      systems = ["x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin"];
+      perSystem = {
+        pkgs,
+        system,
+        ...
+      }: let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+        craneLib = crane.lib.${system};
+        commonArgs = {
+          src = craneLib.cleanCargoSource (craneLib.path ./.);
+          buildInputs = with pkgs;
+            [
+              openssl
+              pkg-config
+              # Add additional build inputs here
+            ]
+            ++ lib.optionals stdenv.isDarwin [
+              # Additional darwin specific inputs can be set here
+              libiconv
+            ];
+        };
+        cargoArtifacts = craneLib.buildDepsOnly (commonArgs
+          // {
+            pname = "grlx-nom-deps";
+          });
+
+        grlx-nom-clippy = craneLib.cargoClippy (commonArgs
+          // {
+            inherit cargoArtifacts;
+            cargoClippyExtraArgs = "--all-targets -- --deny warnings";
+          });
+
+        grlx-nom-nextest = craneLib.cargoNextest (commonArgs
+          // {
+            inherit cargoArtifacts;
+          });
+
+        grlx-nom = craneLib.buildPackage (commonArgs
+          // {
+            inherit cargoArtifacts;
+          });
+      in {
+        checks = {
+          inherit
+            grlx-nom
+            grlx-nom-clippy
+            grlx-nom-nextest
+            ;
+        };
+        formatter = pkgs.alejandra;
+        packages.default = grlx-nom;
+
+        apps.default = flake-utils.lib.mkApp {
+          drv = grlx-nom;
+        };
+
+        devShells.default = pkgs.mkShell {
+          # Additional dev-shell environment variables can be set directly
+          # MY_CUSTOM_DEVELOPMENT_VAR = "something else";
+
+          # Extra inputs can be added here
+          nativeBuildInputs = [
+            commonArgs.buildInputs
+            pkgs.cargo
+            pkgs.rustc
+            pkgs.rust-analyzer
+          ];
+        };
+      };
+    };
+}