codeSplitter team threads: an agent run is a chat room the crew shares and steers #3711

The goal: an agent run is a chat room the team shares. Two people can both prompt and steer it, or talk to each other, and the agent keeps working until something said there changes what it should do. Part of #3423: a thread is the core of a desk in the Agent Office (its "Office Durable Object", "PTY over WebSocket" and "Container lifetime" items).

Done in the first PR (the pipe): claude on the desktop takes its task as stream-json on stdin, and "tell it something" lands at its next step, in the same run. Checked live: a note sent 4 s in was heard in the same run and the agent changed course.

Left, in order

1. Hosted runs hear notes too. sandbox/server.mjs runs the CLI with stdin ignored and answers once it exits. Add a /tell the AgentSandbox Durable Object forwards to the running process's stdin, and have containerSandbox poll the ear and POST each note there. Then set listens for hosted runs (agent-routes.ts).
2. The crew can tell, not just the owner. tell is owner-only (agent-routes.ts, "only the repo's owner can stop, tell, accept or reject"). Let the crew post notes, each tagged with who said it, so the agent knows which teammate is talking.
3. A thread Durable Object per run. Copy the useful half of Qollab's Space (apps/eqosys/src/space.ts: paged history, presence, ChatGate) down to one channel. People's messages and the agent's replies (from its stream-json output) both go in. The run card becomes the thread.
4. Is this for me? Every message reaches the agent today. Try a system-prompt line first ("people here also talk to each other; act only on what changes your task"), and add a cheap Haiku sort (ignore / queue / interrupt) only if that is not enough.
5. Idle threads don't bill. Shut a hosted container down after a few quiet minutes, keep the claude session id on the thread, and bring it back with claude --resume when someone speaks.

Product question settled 2026-11-05: this is part of codeSplitter, not a separate product. It can get its own chat-first front door later, served by the same Worker.