:chan — coordination channels (experimental)

Aliases: channel, irc. Needs both switches:

"experimental": true,
"experiments": { "coordination": true }

Agents working related issues share an IRC-style channel: one per issue family (#CLO-67 — a parent and its sub-issues) and one per project (#proj-cloud-migration — different families, same release). They read and post through in-process MCP tools whose channel and username are fixed at spawn, so an agent can't post as a sibling or reach a family it isn't in.

key	what
j k	move between channels · enter opens one
:chan CLO-67	tail a channel directly, with an input box
type + enter	post as the operator — one message reaches every agent in that channel at its next read
esc	back

With the experiment off the view still shows history, but the input is replaced by a note: posting into a channel nothing is reading is worse than not being able to.

Three senders appear in a channel: agents (as their task username), the operator, and colinear — the system itself, posting deterministic notices such as "the project design changed" from :plan. A colinear message never comes from a session; it is generated text a human can audit in the code.

See COORDINATION.md for the design, the storage layout, and what's deliberately deferred.