Server admins can now point the outer TLS layer at a real CA-signed cert
(e.g. Let's Encrypt fullchain.pem) so the on-wire HTTPS camouflage is
indistinguishable from a normal CA-trusted HTTPS server. The inner Aura
mutual-auth handshake still uses the Aura CA (necessarily — that's where
the PQ mutual auth lives).
- aura-cli config: optional [server.outer_cert] {cert_path, key_path}.
Both fields together (or neither); resolve() reads PEMs and returns
(cert, key) tuple. Absent section -> falls back to reusing the Aura
server cert (v2 behavior, fully back-compat).
- aura-transport: additive MultiServer::bind_with_outer and
TcpServer::bind_with_outer that accept an optional separate outer cert.
Old MultiServer::bind / TcpServer::bind preserved as thin wrappers
(back-compat: existing callers untouched). AuraServer::bind already
took outer cert separately.
- UDP transport doesn't have outer TLS, so outer cert is irrelevant
there — only QUIC + TCP layers benefit.
- 4 new tests (parsing, back-compat, partial-section validation, two-CA
loopback verifying inner peer_id is the inner CN). Workspace: 257 tests
passed (+4), clippy -D warnings clean, fmt clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>