The channels concept (docs/research/alknet-channels/phase-0-findings.md)
was developed in a separate session and is research-phase, not
architecture. The hub spec was inadvertently built assuming a channel
model that doesn't exist yet.
Changes:
- Remove all channels references from hub README (subtitle, channel
model section, channel management bullet, channel proxying section,
'does NOT do' bullet, references)
- Remove OQ-55 (channel/open operation) — channels research has its
own question tracking (OQ-CH-01 through OQ-CH-07)
- Hub spec now describes what it actually provides: peer lifecycle,
aggregated operation env, service discovery. One QUIC connection
per peer carrying the call protocol. No channels, no future
multiplexing, no research references.