glm-5.2
495e04ed43
Channel 0 was dead in both directions (C-01): the call protocol's stream-per-request model (open_bi per call) is incompatible with channel 0's single yield-once BiStream — every call_open_op failed with StreamClosed on the connect side, and channel 0's Connection was a black hole on the accept side. The fix is single-stream call mode (ADR-036 amendment): all EventEnvelope frames are multiplexed on channel 0's one BiStream. Changes: - CallConnection gains single_stream_writer: Option<Arc<SharedFrameWriter>> and new_single_stream() constructor. call_with_payload, subscribe_with_payload, publish_with_payload, and abort branch on is_single_stream() — in single-stream mode they write frames through the shared writer (mutex-serialized) instead of opening a fresh open_bi per call. - Dispatcher::run_loop_single_stream reads frames off channel 0's read half, dispatches call.requested, writes responses through the shared writer, and routes in-flight call.published/call.completed/ call.aborted to the matching Pub sink's chunk_tx by request_id. - ChannelsAdapter::handle's InstallChannelZero hook now receives channel 0's Connection (built by the adapter) and runs the single-stream dispatch loop on it — closing the accept-side black hole. Mux runner is spawned BEFORE install_channel_zero so mux.register(0) can complete. - ChannelClient::from_connection uses CallConnection::new_single_stream and spawns a read pump (read_single_stream_until_closed) that routes channel-0 response frames into the PendingRequestMap via dispatch_envelope — closing the connect-side StreamClosed path. - ADR-036 amendment records the single-stream-mode decision (two-way door: implementation detail, wire format unchanged). Acceptance gate (C-25 #1): three end-to-end tests wire ChannelClient ↔ ChannelsAdapter over a real tokio::io::duplex pair carrying the channels 8-byte chunk header wire format: - channel_0_end_to_end_call_round_trip: a Query op round-trip - channel_0_end_to_end_unknown_op_returns_not_found: NOT_FOUND - channel_0_end_to_end_publish_delivers_chunks: a Pub op with 3 chunks Verification: 437 tests pass (was 434; +3 e2e), clippy clean, fmt clean, doc warnings unchanged (4, pre-existing C-09).