test(scripts): wire scripts/**/*.test.mjs under a vitest runner

241 tests across 16 script test files were wired to NO runner (the
generators vitest config never included them and several used node:test
imports that vitest silently skips). New root vitest.scripts.config.mjs
+ pnpm test:scripts + a CI validate step run them all; node:test imports
converted to vitest keeping node:assert. Split out of 8c88a9a where a
concurrent agent's staged files were swept into the marketing-pages
commit.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

vitest.scripts.config.mjs

@@ -0,0 +1,24 @@
+import { defineConfig } from "vitest/config";
+
+/**
+ * Runner for the root scripts/ test suite (pnpm test:scripts).
+ *
+ * scripts/ is not a workspace package, so `turbo run test` never reaches
+ * these files — this dedicated config wires them to a runner. The suite
+ * runs in CI's validate job alongside the other root-level gates.
+ *
+ * Named vitest.scripts.config.mjs (not vitest.config.*) on purpose so a
+ * bare `vitest` invocation at the repo root does not auto-discover it.
+ */
+export default defineConfig({
+  test: {
+    environment: "node",
+    include: ["scripts/**/*.test.mjs"],
+    clearMocks: true,
+    restoreMocks: true,
+    // Several suites exec child node processes (work CLI, conformance
+    // fixtures) — keep a generous per-test ceiling.
+    testTimeout: 60_000,
+    hookTimeout: 60_000,
+  },
+});