v1.6.0

Added

• references/multi-agent-teams.md: building a production team of agents
  that hand one call between them, from a four-agent helpline tuned on its
  first two days of real calls. It covers when to split (and giving an
  agent only the tools its job needs), how the platform runs a team (edges,
  handoff tools named transfer_to_<target slug>, who joins the call, tools
  staying per agent, the prompt rendered once at call start), the default
  and seamless handoff modes, the router/specialist line and return paths,
  the "taking over a call in progress" section every receiving agent needs,
  tool-only handoff turns, post-call results and automations across agents,
  the API steps, testing each agent and edge with the promptfoo template, a
  go-live checklist, and what to watch on the first real calls.
• What an API key cannot do for a team: create phone tools, set the handoff
  mode (an API-created team starts in default mode), or choose an agent's
  slug, so prompts naming handoff tools are written after the shells exist.

Changed

• agents-and-teams.md, testing.md, troubleshooting.md, and the
  SKILL.md task table point to the new file; the team-splitting tips moved
  there.