release: 1.11.4

[kwhorne]

Release 1.11.4, a security patch release. Bumps the version across Cargo.toml, SERVER_VERSION, both Cargo.locks, the README and the docs, and dates the changelog section.

Since 1.11.3:

• rustls 0.23.45 (RUSTSEC-2026-0285), fix(security): bump rustls to 0.23.45 (RUSTSEC-2026-0285) #141. rustls's TLS 1.3 handshake accepted handshake messages across encryption-level boundaries. The server terminates client TLS with rustls, and every release from 0.9.9 through 1.11.3 shipped an affected version. The advisory was published two days after 1.11.3, which is why its audit was green.
• Dependency patch bumps, build(deps): bump the cargo-patch group across 1 directory with 3 updates #140: clap 4.6.7, ureq 3.4.2, rustix 1.1.5.

No other code change. See CHANGELOG.md.