Introduce a new crypto/ package as the single source of truth for TLS
curve preferences used on every edge-facing connection, and adopt
X25519MLKEM768 as the primary post-quantum key exchange for both QUIC
and HTTP/2:
PQ Prefer (default): X25519MLKEM768, P256Kyber768Draft00, CurveP256
PQ Strict (--post-quantum): X25519MLKEM768, P256Kyber768Draft00
The curve list is identical under FIPS and non-FIPS builds, so
crypto.GetCurvePreferences takes only a features.PostQuantumMode and
returns a fresh slice on every call.
HTTP/2 now applies these curve preferences the same way QUIC does. The
previous PostQuantumStrict rejection in serveHTTP2 and the forced
QUIC-only selection in NewProtocolSelector are removed since both
transports support the same post-quantum curves; the needPQ parameter
is dropped from NewProtocolSelector accordingly.
Also fix a shared tls.Config race: both the QUIC and HTTP/2 paths now
Clone() the per-protocol entry from TunnelConfig.EdgeTLSConfigs before
mutating CurvePreferences instead of writing through the shared map
entry.
Legacy Kyber draft curve X25519Kyber768Draft00
and the unused removeDuplicates helper are removed along with the old
supervisor/pqtunnels.go / _test.go files.
AGENTS.md is updated with guidance on the new crypto/ package, the
cfdcrypto import alias, the tls.Config cloning rule, and the lint
workflow implications of .golangci.yaml's whole-files: true setting.
Going forward, the only protocols supported will be QUIC and HTTP2,
defaulting to QUIC for "auto". Selecting h2mux protocol will be forcibly
upgraded to http2 internally.
lneto