Stream an agent run live

Server-sent events for a run, live: `text/event-stream` with three event kinds. - `timeline` — a durable event, same shape as `GET /v1/agent-runs/{id}/timeline`, with the SSE `id` set to the event id. Delivery is at-least-once: dedupe by id, and reconnect with `Last-Event-ID` to resume. - `live` — provisional activity while the agent works: `{kind: "text_delta", stepId, text}` streams the agent's words as it writes them; `{kind: "tool_started"|"tool_finished", toolCallId, toolName, ok?}` announce tool activity. Never durable — a reconnect replays none of it. - `status` — `{status}` in the run-status vocabulary, sent on connect and on every change. Terminal status ends the stream. Streams are capped at five minutes — reconnect to continue; `Last-Event-ID` carries the durable cursor. Reading a `queued` run's stream starts it, exactly like reading the run. curl it: `curl -N -H "authorization: Bearer $KEY" …/v1/agent-runs/agr_…/stream` **Learn more:** [Agents guide](https://docs.cloudraker.com/capabilities/agents)