elixir_quic_http3

Beta HTTP/3 client application protocol for the elixir_quic transport.

The source was imported from gsmlg-dev/ex_quic@14974913390e12d03a78a2903d18e55a04fa89d6 and extended in the http_fetch umbrella. QuicHttp3.Session owns HTTP/3 control/request streams, settings, response framing and QPACK; QuicHttp3.Transport.Quic supplies the native transport. The shared runtime owns pooling and application delivery.

QuicHttp3.capabilities/0 reports status: :beta, http3: true, qpack: true, qpack_profile: :static_literal and qpack_huffman: true. The initial profile advertises zero dynamic-table capacity and zero blocked streams. Dynamic QPACK, 0-RTT, connection migration, WebSocket over HTTP/3 and WebTransport are explicitly unsupported. Raw Quic.capabilities().http3 remains false.

Fetch and EventSource select this runtime explicitly with http_version: :http3. HTTPS and verified peer identity are required; there is no protocol fallback. See the Fetch contract for bodies, deadlines, cancellation, redirects, trailers and telemetry.

Beta capability reporting does not establish complete protocol conformance, production readiness or publication. Independent peer, artifact, load and canary results are tracked separately in the implementation audit and acceptance record; final acceptance remains subject to those gates.