DL-164

Start-half (Active): starting an agent is the lifecycle operation (startAgent → composite SpawnAgent), which rejects when the target agent already holds a live session; an agent owns multiple cards, so the SessionBinding map is keyed by card (workstreamId = Issue.id), not agent, inside one container / one live session. Add-half superseded by DL-185 (Matt, 2026-08-07): the manual add-a-workstream board mutation (addWorkstream) and UI-side agent creation (CommsService.CreateAgent) are dropped.

Status: Superseded by DL-253 (Matt, 2026-08-25)

Record: ../../agent/compass-spawn-control/design.md#control-flow-start-an-agent-spawnagent