feat: add nix flake for development

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -89,4 +89,7 @@ tidal*.json
 *.mpd
 
 # Local devtools
-devtools
+devtools
+
+# Nix / direnv
+.direnv/

flake.nix

@@ -0,0 +1,41 @@
+{
+  description = "Unofficial API for TIDAL music streaming service.";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+  };
+
+  outputs = inputs @ {
+    nixpkgs,
+    flake-parts,
+    ...
+  }:
+    flake-parts.lib.mkFlake {inherit inputs;} {
+      systems = nixpkgs.lib.systems.flakeExposed;
+      perSystem = {
+        pkgs,
+        ...
+      }: let
+        python = pkgs.python3;
+        buildInputs =
+          [
+            python
+          ]
+          ++ (with pkgs; [
+            # build / dev
+            poetry
+            ruff
+          ]);
+      in {
+        devShells.default = pkgs.mkShell {
+          packages = buildInputs;
+          shellHook = ''
+            [ ! -d .venv ] && python -m venv .venv
+            source .venv/bin/activate
+            poetry install --quiet 2>/dev/null
+          '';
+        };
+      };
+    };
+}