Function spawn_agent 

pub async fn spawn_agent(
    __arg0: State<AppState>,
    __arg1: Path<String>,
    principal: Option<Extension<Principal>>,
    __arg3: Json<SpawnBody>,
) -> Result<(StatusCode, Json<SpawnedResponse>), ApiError>

POST /api/workspaces/{workspace}/agents — spawn an agent (worktree by default).

Routed through the FleetProvider seam: LocalFleet::ensure_agent delegates to the same FleetManager::spawn_agent this handler called directly before, so behavior is unchanged. unattended (#238) runs the agent with no permission gate, so it takes the admin scope (ADR-0010) rather than the operate a spawn otherwise needs — a per-field rule the route-level scope table can’t express. The principal is absent only when auth is disabled entirely, which is already a trusted loopback deployment, so that case is allowed and still audited.