docs(env): note that / and /repos need BUZZ_SERVE_GIT_WEB_GUI

[TheSeydiCharyyev]

Summary

The BUZZ_WEB_DIR comment in .env.example says that setting it makes the relay serve "the web frontend at / for browser requests". Setting it alone does not do that, so anyone following the file ends up with a relay that answers / with JSON and concludes the web bundle is broken.

What the code actually does — crates/buzz-relay/src/router.rs:

fn should_serve_spa(path: &str, serve_git_web_gui: bool) -> bool {
    is_invite_landing_path(path) || (serve_git_web_gui && is_git_web_gui_path(path))
}

fn is_git_web_gui_path(path: &str) -> bool {
    path == "/" || path == "/repos" || path.starts_with("/repos/")
}

nip11_or_ws_handler gates its Accept: text/html branch for / on the same flag, and serve_git_web_gui is read from BUZZ_SERVE_GIT_WEB_GUI in crates/buzz-relay/src/config.rs with .unwrap_or(false). So with only BUZZ_WEB_DIR set, a browser requesting / gets the NIP-11 document.

/invite/{code} does work with BUZZ_WEB_DIR alone, since is_invite_landing_path is checked unconditionally. The comment now says that, and documents BUZZ_SERVE_GIT_WEB_GUI — which .env.example did not mention at all.

The wording follows the table already in TESTING.md, which describes both variables correctly today; this only brings .env.example in line with it.

Related issue

Fixes #3815. No open PR touches these lines — #3777 also edits .env.example, but adds BUZZ_ADMIN_WEB_DIR in a different section.

Testing

Documentation only; no code changes, so no behaviour to test. The claim is verified against the repository's own unit test rather than by reasoning alone — crates/buzz-relay/src/router.rs contains:

#[test]
fn invite_is_always_served_but_git_gui_requires_opt_in() {
    assert!(should_serve_spa("/invite/payload.mac", false));
    assert!(!should_serve_spa("/", false));
    assert!(!should_serve_spa("/repos/example", false));
    assert!(should_serve_spa("/", true));
    assert!(should_serve_spa("/repos/example", true));
}

That test is exactly the behaviour the old comment contradicted.

[Chessing234]

good doc catch. can you also mention it next to BUZZ_SERVE_GIT_WEB_GUI so both comments point at each other?

[TheSeydiCharyyev]

Both comments are already adjacent and point at each other — this PR adds the BUZZ_SERVE_GIT_WEB_GUI block directly under BUZZ_WEB_DIR. The first says / and /repos/... additionally require the flag; the second says the flag has no effect unless BUZZ_WEB_DIR is set. There was no BUZZ_SERVE_GIT_WEB_GUI entry in .env.example before this PR, so there is no other place to link from.

One thing worth taking from it though: the first block said "the flag below", which breaks if the lines ever move. Pushed 5957f29 naming BUZZ_SERVE_GIT_WEB_GUI directly.

For reference, Dockerfile:147-149 and the TESTING.md table already describe this correctly — .env.example was the only place that did not.