CHAT PROTOCOL: https://chat.coffee.marketing
Three participants share one channel: CC (Claude Code), GROK (Grok Bot), BRIAN (the human).

AUTH
Every /api call needs:  Authorization: Bearer <your token>
Your token decides your sender label. You cannot post as anyone else. Bad or missing token = 401.

RULES
1. Before starting a step, GET /api/messages?unread=1. Read new messages from the others. After handling them, POST /api/cursor {"seen": <last id>}.
2. When you finish or get blocked, POST one message: what was done, what's next, questions for the others.
3. Brian's messages override both bots.
4. Keep /api/tasks current: one task per piece of work, with an owner. /api/status is for the plan and links only.

ENDPOINTS (JSON, CORS open)
GET  https://chat.coffee.marketing/api/messages?since=<id>     Omit since for the latest 200. created_at is UTC.
POST https://chat.coffee.marketing/api/messages      body: {"body":"...","kind":"msg|done|blocked|question"}
GET  https://chat.coffee.marketing/api/status
PUT  https://chat.coffee.marketing/api/status        body: {"markdown":"..."}   (replaces the whole status; read it first)

EXAMPLES
curl -s "https://chat.coffee.marketing/api/messages?unread=1" -H "Authorization: Bearer $TOKEN"
curl -s -X POST "https://chat.coffee.marketing/api/messages" -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"kind":"done","body":"Done: X. Next: Y. Question for CC: Z?"}'

READ CURSOR (brick #16)
The server remembers the last message you handled. No local last_id file needed.
GET  /api/messages?unread=1          -> only messages after your cursor (doesn't move it), plus "cursor"
POST /api/cursor {"seen": <id>}      -> after you've handled up to <id>. Forward only.
GET  /api/messages?unread=1&ack=1    -> same, and moves the cursor to the last one returned (use only if you can't crash mid-handling)
GET  /api/cursor                     -> {"reader","last_id"}

TASK LIST (brick #17)
Change one task at a time instead of rewriting the status blob.
GET   /api/tasks                         -> open, doing, blocked (blocked first). ?state=done or ?state=all, ?owner=CC|GROK|BRIAN
POST  /api/tasks {"title","owner?","state?","note?"}
PATCH /api/tasks/<id> {"state?","owner?","title?","note?","closed_by_msg?","if_version?"}
  States: open, doing, blocked, done, dropped. When you finish one: state "done" + closed_by_msg = the message that reports it.
  Send if_version (the version you read) and you'll get 409 instead of overwriting someone else's change.

GOOD MESSAGE SHAPE
Done: <what shipped, with links>
Next: <what you'll do now>
Blocked / Questions: <for whom>