feat: use jj-starship

pkgs/jj-starship.nix

@@ -0,0 +1,40 @@
+{
+  lib,
+  rustPlatform,
+  fetchFromGitHub,
+  pkg-config,
+  libgit2,
+  zlib,
+  versionCheckHook,
+  withGit ? true,
+}:
+
+rustPlatform.buildRustPackage (finalAttrs: {
+  pname = "jj-starship";
+  version = "0.7.1";
+
+  src = fetchFromGitHub {
+    owner = "dmmulroy";
+    repo = "jj-starship";
+    rev = "v${finalAttrs.version}";
+    hash = "sha256-NLds7i1ZmscicaNLmkZCWmc7A+367BXxGioRd4yYof8=";
+  };
+
+  cargoHash = "sha256-i7x/y+BkKH+Xj1bU4RRe9fcteabB+4uAgJuW3x5/jv4=";
+  buildNoDefaultFeatures = !withGit;
+
+  nativeBuildInputs = [ pkg-config ];
+
+  buildInputs = [ zlib ] ++ lib.optionals withGit [ libgit2 ];
+
+  doInstallCheck = true;
+  nativeInstallCheckInputs = [ versionCheckHook ];
+
+  meta = {
+    description = "Unified Starship prompt module for Git and Jujutsu repositories that is optimized for latency";
+    homepage = "https://github.com/dmmulroy/jj-starship";
+    changelog = "https://github.com/dmmulroy/jj-starship/releases/tag/v${finalAttrs.version}";
+    license = lib.licenses.mit;
+    mainProgram = "jj-starship";
+  };
+})