chore(deps): update Cloudflare Worker tooling (#1574)

## Description

Update Wrangler, Cloudflare Workers types, and the Cloudflare Vitest pool for Node 24, Vite 8, and Vitest 4 compatibility. Existing Worker test APIs and compatibility date remain valid.

Closes codemem-jnd6.6.

## Type of Change

- [ ] 🚀 Feature (new functionality)
- [ ] 🐛 Bug fix (fixes an issue)
- [ ] 📚 Documentation (docs-only change)
- [x] 🔧 Maintenance (refactor, chore, CI, etc.)
- [ ] 🧪 Testing (test-only changes)

## Testing

- [x] Relevant checks pass locally (`pnpm run tsc`, `pnpm run lint`, `pnpm run test`)
- [ ] Added/updated tests for changes
- [x] Manually verified changes work as expected

Additional checks: Worker typecheck, Wrangler dry-run bundle, 12 Node tests, 6 Worker integration tests, Snyk high-severity SCA scan.

Known follow-up: migrate the terminal `@cloudflare/vitest-pool-workers` package to `@cloudflare/vitest-plugin`; the current pool also pins an older test-only workerd than direct Wrangler.

## Checklist

- [x] Code follows project style (`pnpm run lint` passes for touched files)
- [x] Self-review completed
- [x] Documentation updated (not needed)
- [x] No new warnings introduced