docker-mailbox v0.2.0 — flat MCP tool set MCP now exposes one flat tool catalog. Per-mailbox tools take `mailbox` as a parameter (name or address) instead of being namespaced. Tool count is now O(1) instead of O(N) in mailbox count — agents can scale to 100+ inboxes without drowning in tool definitions. BREAKING for MCP clients: `<name>__list_messages` → `list_messages(mailbox=...)`.