Correlates call.responded events back to call.requested by request ID
(stream-agnostic per ADR-012). Manages Call (oneshot) and Subscribe
(mpsc) entries with timeout-based eviction and fail_all on connection
close. Unknown request IDs are silently discarded.
Create crates/alknet-call with Cargo.toml, lib.rs, and module skeletons
for the registry (spec, context, registration, env, discovery) and
protocol (wire, pending, connection, adapter, abort) subsystems. Add the
crate to the workspace members list. Depends on alknet-core (workspace
path), irpc (workspace dep), tokio, serde, serde_json, async-trait,
tracing, thiserror, uuid, and futures. Implements ProtocolHandler on
ALPN alknet/call per docs/architecture/crates/call.
