Start Demo Job

Start a demo job for the caller’s workspace and return its id (202 Accepted). Requires auth — the job is stamped with the principal’s tenant and is only visible to that tenant (RLS). The caller then opens the SSE stream below to watch it.

We generate the job_id HERE so we can hand it back to the browser AND pass it into the workflow — guaranteeing the executor records progress on the very job the SSE stream is about to follow. The job row is persisted (under the tenant’s RLS context) BEFORE we trigger work, so the worker’s first step always finds it.