chore(tooling): add nix flake and reconfigure some stuff for neovim

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false

.envrc

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+if ! has nix_direnv_version || ! nix_direnv_version 2.2.1; then
+  source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/2.2.1/direnvrc" "sha256-zelF0vLbEl5uaqrfIzbgNzJWGmLzCmYAkInj/LNxvKs="
+fi
+
+watch_file flake.nix
+watch_file flake.lock
+if ! use flake . --no-pure-eval; then
+  echo "direnv could not be built. The direnv environment was not loaded. Make the necessary changes to flake.nix and hit enter to try again." >&2
+fi

.vscode/launch.json

@@ -1,15 +1,11 @@
 {
-    // Use IntelliSense to learn about possible attributes.
-    // Hover to view descriptions of existing attributes.
-    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
-    "version": "0.2.0",
-    "configurations": [
-        {
-            "name": "C#: Looking Glass",
-            "type": "dotnet",
-            "request": "launch",
-            "projectPath": "${workspaceFolder}/LookingGlass.csproj"
-        }
-
-    ]
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "C#: Looking Glass",
+      "type": "coreclr",
+      "request": "launch",
+      "program": "./bin/Debug/net9.0/LookingGlass.dll"
+    }
+  ]
 }

flake.lock

@@ -0,0 +1,25 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1738680400,
+        "narHash": "sha256-ooLh+XW8jfa+91F1nhf9OF7qhuA/y1ChLx6lXDNeY5U=",
+        "rev": "799ba5bffed04ced7067a91798353d360788b30d",
+        "revCount": 747653,
+        "type": "tarball",
+        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.747653%2Brev-799ba5bffed04ced7067a91798353d360788b30d/0194d302-29da-7009-8f43-5b8a58825954/source.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://flakehub.com/f/NixOS/nixpkgs/0.1.%2A.tar.gz"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,41 @@
+{
+  description = "A Nix-flake-based C# development environment";
+
+  inputs.nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.1.*.tar.gz";
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      supportedSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      forEachSupportedSystem =
+        f:
+        nixpkgs.lib.genAttrs supportedSystems (
+          system:
+          f {
+            pkgs = import nixpkgs { inherit system; };
+          }
+        );
+    in
+    {
+      devShells = forEachSupportedSystem (
+        { pkgs }:
+        {
+          default = pkgs.mkShell {
+            packages = with pkgs; [
+              dotnet-sdk_9
+              omnisharp-roslyn
+              mono
+            ];
+            shellHook = ''
+              export ASPNETCORE_ENVIRONMENT=Development
+            '';
+          };
+        }
+      );
+    };
+}