fix(runtime): anchor bundled plugin npm staging to active node

test/scripts/stage-bundled-plugin-runtime-deps.test.ts

@@ -0,0 +1,53 @@
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+import { resolveNpmRunner } from "../../scripts/stage-bundled-plugin-runtime-deps.mjs";
+
+describe("resolveNpmRunner", () => {
+  it("anchors npm staging to the active node toolchain when npm-cli.js exists", () => {
+    const execPath = "/Users/test/.nodenv/versions/24.13.0/bin/node";
+    const expectedNpmCliPath = path.resolve(
+      path.dirname(execPath),
+      "../lib/node_modules/npm/bin/npm-cli.js",
+    );
+
+    const runner = resolveNpmRunner({
+      execPath,
+      existsSync: (candidate: string) => candidate === expectedNpmCliPath,
+      platform: "darwin",
+    });
+
+    expect(runner).toEqual({
+      command: execPath,
+      args: [expectedNpmCliPath],
+      shell: false,
+    });
+  });
+
+  it("falls back to bare npm when npm-cli.js is unavailable", () => {
+    expect(
+      resolveNpmRunner({
+        execPath: "/tmp/node",
+        existsSync: () => false,
+        platform: "linux",
+      }),
+    ).toEqual({
+      command: "npm",
+      args: [],
+      shell: false,
+    });
+  });
+
+  it("keeps shell mode for bare npm fallback on Windows", () => {
+    expect(
+      resolveNpmRunner({
+        execPath: "C:\\node\\node.exe",
+        existsSync: () => false,
+        platform: "win32",
+      }),
+    ).toEqual({
+      command: "npm",
+      args: [],
+      shell: true,
+    });
+  });
+});