Function backgroundLauncherFor

internal/app/do.go:538–546

backgroundLauncherFor returns the harness's BackgroundLauncher capability, or a clean error if the harness can't host background sessions. This is the capability gate for $FLOW_TERM=bg: flow never silently falls back to a terminal tab when the pinned harness lacks the capability.

(h harness.Harness)

	if _, err := db.Exec(
		`UPDATE workdirs SET last_used_at = ? WHERE path = ?`,
		now2, task.WorkDir,
	); err != nil {
		fmt.Fprintf(os.Stderr, "warning: bump workdir last_used_at: %v\n", err)
	}

	if needsBootstrap {
		fmt.Printf("Spawned %s (session %s)\n", task.Slug, sessionID)
	} else {
		fmt.Printf("Resumed %s (session %s)\n", task.Slug, sessionID)
	}
	return 0
}