- Add end-to-end test suite covering HTTP tunnel round-trip, POST
forwarding, unknown tunnel 404, duplicate name rejection, unauthorized
access, info endpoint, multi-tunnel routing, and graceful shutdown
- Fix server graceful shutdown by closing TCP listener on context cancel
- Fix data race in pkg/maps Entries() iterator by holding RLock
- Rewrite README with architecture, configuration, and usage docs
- Add AGENTS.md with project conventions and architecture guide
- Update flake.nix (add gopls) and flake.lock
