Add Deno reusePort section with app code, Dockerfile, and nixpacks.toml
examples. Extend coverage to Bun and Deno throughout: description,
problem table, fix table, and verification section. Minor copy improvements
for platform-neutral phrasing. Update dev server port to 5173 in jean.json.
- add new S3 knowledge base page for Supabase Storage setup and verification
- link Supabase guide in VitePress sidebar and S3 introduction page
- update S3 introduction provider list/description wording
- refresh lockfile dependency versions and add `jean.json` dev runner config