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>

package.json

@@ -12,6 +12,7 @@
     "lint": "turbo run lint",
     "test": "turbo run test",
     "test:e2e": "turbo run test:e2e",
+    "test:scripts": "vitest run --config vitest.scripts.config.mjs",
     "test:stories": "turbo run test:stories",
     "test:visual": "pnpm --filter @repo/storybook exec concurrently -k -s first -n 'SB,VRT' -c 'magenta,blue' 'pnpm --filter @repo/storybook exec http-server storybook-static --port 6006 --silent' 'pnpm --filter @repo/storybook exec wait-on tcp:6006 && pnpm exec playwright test --config ../../playwright.config.ts'",
     "typecheck": "turbo run typecheck",
@@ -45,6 +46,7 @@
     "prettier": "^3.5.0",
     "turbo": "^2.4.0",
     "typescript": "^5.8.0",
+    "vitest": "^3.2.7",
     "zod": "^3.25.0"
   },
   "lint-staged": {