rust-web-server 18.4.0

Single-binary web server and reverse proxy: automatic HTTPS (Let's Encrypt), HTTP/1.1, HTTP/2 and HTTP/3, load balancing, auth and rate limiting, configured in one TOML file. Also a Rust library: routing, middleware, MCP server, ORM, background jobs. No hyper, no Tower; HTTP/2 and HTTP/3 framing via h2 and quinn.

Documentation

## What and why

<!-- What does this change, and why? Link the issue: "Fixes #123". -->

## Checklist

- [ ] Tests for the change (happy path and a failure case); `cargo test` passes
- [ ] Docs page under docs/ updated, CHANGELOG.md entry, `python3 ci/gen_llms.py` rerun
- [ ] No new compiler warnings