feat(radar): add radar Kubernetes UI package v1.5.10

Add radar v1.5.10 — a modern Kubernetes visibility tool providing
topology, event timeline, service traffic, resource browsing, Helm
management, and GitOps support.

Uses pre-built binary from GitHub releases.

Closes: nix-overlay-2lr

packages/radar/default.nix

@@ -0,0 +1,5 @@
+{
+  pkgs,
+  ...
+}:
+pkgs.callPackage ./package.nix { }

packages/radar/package.nix

@@ -0,0 +1,47 @@
+{
+  lib,
+  stdenv,
+  fetchurl,
+}:
+
+let
+  version = "1.5.10";
+in
+stdenv.mkDerivation rec {
+  pname = "radar";
+  inherit version;
+
+  src = fetchurl {
+    url = "https://github.com/skyhook-io/radar/releases/download/v${version}/radar_v${version}_linux_amd64.tar.gz";
+    hash = "sha256-B+u3jdnScJUzsnoPAFPEk0dYFNDPe9hhvY1OaXttj9c=";
+  };
+
+  sourceRoot = ".";
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp kubectl-radar $out/bin/radar
+    chmod +x $out/bin/radar
+  '';
+
+  doCheck = false;
+
+  passthru = {
+    category = "Kubernetes";
+    updateScript = [
+      "nix-update"
+      "--flake"
+      ".#radar"
+    ];
+  };
+
+  meta = with lib; {
+    description = "Modern Kubernetes visibility — topology, event timeline, service traffic, resource browsing, Helm management, and GitOps support";
+    homepage = "https://github.com/skyhook-io/radar";
+    changelog = "https://github.com/skyhook-io/radar/releases/tag/v${version}";
+    license = licenses.asl20;
+    sourceProvenance = with sourceTypes; [ binaryNativeCode ];
+    mainProgram = "radar";
+    platforms = [ "x86_64-linux" ];
+  };
+}