chore(tooling): port upstream infra/tooling audit fixes

Ports the kept-file portions of the upstream infra audit-fix subset onto
the clean-slate template branch (auth-only shape; workspaces feature never
existed here, so its package.json edit is skipped):

- resolve the root playwright config in pnpm test:visual (S8)
- prune dead VERCEL_ENV from turbo.json globalEnv (S9)
- drop the duplicate chromium install in the storybook CI job (S10)
- wire scripts/**/*.test.mjs under a dedicated vitest runner
  (vitest.scripts.config.mjs + pnpm test:scripts + CI validate step);
  convert node:test imports to vitest keeping node:assert
- ignore *.tsbuildinfo repo-wide and untrack the committed build state
- align every @trpc/* range on ^11.18.0 so the workspace resolves to a
  single version (peer-warning-free install)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

.gitignore

@@ -10,6 +10,9 @@ node_modules
 # Turbo
 .turbo
 
+# TypeScript incremental build state
+*.tsbuildinfo
+
 # Build outputs
 dist
 build