Three simplifications to the channels spec, all flowing from the review:
1. Substrate simplification (ADR-071 revised): the 9-byte chunk header is
used in ALL substrates — in-line (TCP+TLS, WebTransport), native (QUIC
bidi streams), and multi-connection. The ChannelsAdapter reads headers
off every bidi stream it accepts; the transport's native multiplexing
is a performance optimization (independent flow-control windows), not a
protocol change. One wire format, one code path, one handler experience.
The channel_id in the header is the correlation key across substrates.
2. Stream_type decomposition (ADR-071 revised): every stream_type is
unidirectional. Bidirectionality is two stream_types (write + read), not
one 'bidirectional' stream_type. Grouped in threes: 0/1/2 = data
write/read/err, 3/4/5 = control write/read/err, % 3 formula. This
resolves the TTY control channel's 'not actually bidirectional' flaw —
control is now 3 (write, client→server) + 4 (read, server→client), each
with its own reassembly buffer and EOF. Channel 0 uses [0,1] (call frames
bidirectional via 0=in, 1=out). TTY uses [0,1,2,3,4]. ADR-072, 073, 074,
077 updated for the new stream_type assignments.
3. Sub-crate decomposition (ADR-081 new): channels-core (pure multiplexer —
wire format, demux/mux, ChannelBidiStreamSource, ChannelManager; depends
on alknet-core only, no call dependency, ALPN-blind) / channels-call
(channel 0 pre-negotiation + lifecycle op registrations; depends on
channels-core + alknet-call) / channels-hub (relay) / channels-worker
(ChannelClient). Isolates the call-protocol coupling from the pure
multiplexer so the dependency graph is honest.
ADR-077 (TTY inside channels) updated: TTY now uses 5 sub-streams [0,1,2,3,4]
with control properly bidirectional via 3/4; amends ADR-052's stream_type
assignments for direct mode too (direct alknet/tty now uses 0-4, not 0-3).
Spec docs updated: channels-wire, channels-connection, channels-adapter,
channel-operations, overview, README.
glm-5.2