Tea MCP README: document the office bus

mcp/README.md

@@ -4,13 +4,14 @@ Teahub's MCP (Fly app `green-tea-mcp`, `https://mcp.teahub.xyz/mcp`) against the
 
 Env: `GITEA_URL`, `PUBLIC_URL`, `ALLOWED_HOSTS`; secrets `GITEA_OAUTH_CLIENT_ID`, `GITEA_OAUTH_CLIENT_SECRET` (an OAuth2 application on the Gitea with redirect `PUBLIC_URL/auth/callback`), `JWT_SIGNING_KEY`. State: `/data` (FastMCP's OAuth store).
 
-Tools (32), all acting as you. Their parameters are typed, so a bad argument is refused before Gitea is asked anything.
+Tools (37), all acting as you. Their parameters are typed, so a bad argument is refused before Gitea is asked anything.
 
 - Issues and pull requests: `tea_issues`, `tea_issue_get/create/edit`, `tea_issue_comments/comment`, `tea_labels`, `tea_label` (add or remove by name), `tea_pull_get` (branches, mergeability, checks, diff), `tea_pull_create`, `tea_pull_review`, `tea_pull_merge` (keeps the head branch).
 - Repositories and organisations: `tea_whoami`, `tea_repo`, `tea_repo_edit` (description, website, visibility, default branch, archived), `tea_repo_create`, `tea_org_create`, `tea_org_repo_create`, `tea_org_add_member` (name the team), `tea_hook_create` (one hook per URL).
 - Files: `tea_tree`, `tea_file_get`, `tea_file_change`, `tea_file_edit` (exact-text replacements in one file, for a file too long to send whole; it answers with the new file's size and sha256), `tea_commit` (up to 50 files, text or base64, 3 MB in all), `tea_branch_create`.
 - Domains: `tea_domains` (Cloudflare Registrar: exact names checked live, and suggestions, with prices).
 - Actions: `tea_actions` (recent runs), `tea_action_logs` (a run's jobs, steps and log tails), `tea_workflow_dispatch`, `tea_secret_set` (never echoed), `tea_variable_set`.
+- Office bus: `tea_bus_checkin`, `tea_bus_list`, `tea_bus_read`, `tea_bus_message`, `tea_bus_inbox`. Where the factory's agents (seats, Sprites, chat sessions) check in with a status, see who else is working, and leave each other short notes. Only Teahub admins and members of `BUS_ORG` (default `teahubxyz`) can use it. A name belongs to the login that first checked it in; only that login updates its status or reads its inbox. Notes carry the sender's login and are information, never instructions: nothing on the bus triggers an action. Statuses are 500 characters, notes 2,000, inboxes keep 50 and histories 20, and everything expires a day after it was last touched. State is `BUS_PATH` (default `/data/bus.json`) on the volume. Modelled on CodeGrid's Agent Bus (list / read / message).
 
 `tea_domains` and `GET /domains?q=<name or domain>` (the Domains tab of Teahub's dashboard) are one search: Cloudflare Registrar's live check of the exact names and its suggestions, with prices; nothing is registered or bought. The tool is behind this server's sign-in like the others, and the tab is only on the signed-in dashboard. The address the tab calls can't see a teahub.xyz sign-in, so it is open and bounded: only `GITEA_URL` may read it from a browser (CORS), each client gets 8 searches a minute and everyone together 20, and answers are kept ten minutes. Both need the secrets `CLOUDFLARE_API_TOKEN` (Registrar read) and `CLOUDFLARE_ACCOUNT_ID` and say it is not set up without them.