trillium-http-v1.1.0

This release adds http/2 support.

Added

• pub mod h2 — HTTP/2 protocol primitives: HPACK encode/decode, h2 framing, H2Connection, H2Driver, H2Transport. HTTP/2 is automatically negotiated when ALPN selects h2 or via prior-knowledge cleartext ("h2c"). 146/146 h2spec cases pass.
• HTTP/2 extended CONNECT (RFC 8441) — opt in via HttpConfig::with_extended_connect_enabled(); required for WebSockets-over-h2.
• KnownHeaderName::Refresh
• Conn::h2_connection(), Conn::h2_stream_id(), Conn::h3_stream_id() — for handlers that want to interact with the underlying h2/h3 stream
• Upgrade::h2_connection, Upgrade::h2_stream_id, Upgrade::h3_stream_id (and _mut / set_ / with_ / take_ variants where applicable) — used by trillium-websockets for WS-over-h2 (RFC 8441)
• Various HttpConfig::h2_* tuning knobs: h2_initial_connection_window_size, h2_initial_stream_window_size, h2_max_stream_recv_window_size, h2_max_concurrent_streams, h2_max_frame_size
• HttpConfig::dynamic_table_capacity (and setter / with_ / _mut variants) — HPACK/QPACK encoder dynamic table capacity, shared between h2 and h3
• HttpConfig::recent_pairs_size (and setter / with_ / _mut variants) — per-connection ring size for the HPACK/QPACK encoder's recent-pairs predictor
• HttpConfig::h3_blocked_streams (and setter / with_ / _mut variants) — maximum number of HTTP/3 streams that may be blocked waiting for QPACK dynamic-table updates
• Upgrade::response_headers: Headers — the response headers that had been set on the underlying Conn before the upgrade was negotiated. These have already been sent to the peer; preserved here so post-upgrade code can inspect what was sent. response_headers_mut, set_response_headers, with_response_headers, and into_response_headers round out the accessor surface.
• Upgrade::status (with _mut / set_ / take_ / with_ variants) — Option<Status> carrying the response status sent before the upgrade
• Upgrade::start_time (with _mut / set_ / with_ variants) — Instant recording when the Conn that became this Upgrade was constructed
• H3Connection::peer_settings_ready() -> PeerSettingsReady<'_> (gated on the unstable feature) — async future that resolves to Some(H3Settings) once the inbound control stream has applied the peer's SETTINGS frame, or None if the connection shut down before SETTINGS arrived. Required for senders of extended-CONNECT requests (RFC 9220 §3 — the spec forbids sending a :protocol HEADERS until the peer has advertised SETTINGS_ENABLE_CONNECT_PROTOCOL). On a pooled connection that has already exchanged SETTINGS, the future resolves on the first poll. Multiple awaiters on the same connection are supported.

The existing sync H3Connection::peer_settings(&self) -> Option<&H3Settings> accessor is unchanged.