`unitd` drop-in replacement: FreeUnit (community fork of NGINX Unit)

[freeunitx]

Hi! SNUnit uses the external application type, so it works with any unitd-compatible server.

FreeUnit is the community LTS fork of NGINX Unit (Apache 2.0), actively maintained after the original project was archived. It's a drop-in replacement — same control API, same config schema, same external protocol.

Why this may matter for SNUnit users:

• Chunked proxy fixes — relay UAF crash on client abort (Implement Tapir interpreter #72, unitd router process crash whilst using proxy nginx/unit#828), premature upstream EOF masking, duplicate TE header handling. These affect any proxy path (e.g. SNUnit behind a reverse proxy).
• OpenTelemetry (--otel) built in.
• PHP 8.4/8.5 first-class, WASI 0.2 components.
• Active development — 8-language support, Debian trixie Docker images, unitctl Rust CLI.

No code changes needed in SNUnit. Users install FreeUnit's unitd package instead of the archived NGINX Unit one — same binary name, same flags, same control socket. Docker: ghcr.io/freeunitorg/freeunit:latest-minimal.

Would you be open to mentioning FreeUnit as an alternative unitd in the README? Happy to send a PR.