[overtrue]

Summary

Keep the connection-policy explanation for an unavailable authenticator and render its private helper name as code. The public module page currently fails under rustdoc -D warnings because it links to that private helper. The fix changes a single rustdoc line.

Follow-up to #1594 and #1585.

Verification

$ cargo fmt --all --check
$ cargo clippy --workspace --all-targets -- -D warnings
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 1m 02s
$ cargo test --workspace
    Finished `test` profile [unoptimized + debuginfo] target(s) in 6m 21s
test result: ok. 5 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.09s
$ cargo xtask verify --crate rustfs-gateway
verify: crate rustfs-gateway fast runtime scope; compile-time, representative conformance, and million-key RSS contracts remain in cargo test --workspace build compiled 67 crate(s) in 35.78s outside the budget
verify: crate rustfs-gateway fast runtime scope; compile-time, representative conformance, and million-key RSS contracts remain in cargo test --workspace, loop 1 of 2 passed in 21.67s
verify: crate rustfs-gateway fast runtime scope; compile-time, representative conformance, and million-key RSS contracts remain in cargo test --workspace, loop 2 of 2 passed in 6.35s
$ RUSTDOCFLAGS="-D warnings" cargo doc --workspace --no-deps
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 57.10s

With the original link, the warnings-as-errors documentation build reported public documentation for close links to private item after_unavailable. The patched workspace build passed.

Role Verdicts

• simplicity-adversary: attacked the public policy wording and helper visibility — no break found

Breaking Change

• BREAKING — this PR touches a protected file or changes a public contract.

Checklist

• The four-command gate passed (fmt, clippy, test, cargo xtask verify)
• New or changed public API has rustdoc
• Negative test cases outnumber positive ones
• Every new assertion was mutated — the implementation was broken on purpose and the assertion
  went red. The PR description names which ones
• No Protected File touched; if one was, the PR description contains BREAKING and a migration path
• No unsafe introduced
• No inventory / linkme introduced
• No #[non_exhaustive] added to a DTO
• No s3s code copied; behavioural evidence is URL + self-written summary
• No credentials, signatures, or expected-signature values reachable from logs or error bodies
• No plan document, analysis report, or working note committed
• Commits follow Conventional Commits; PR title ≤72 characters
• A Handoff comment has been appended to the issue