The build loop opens a lane for every ready spec step whatever the ceiling, making its worktree and brief at once (schedule.go move, the eager opening the parallel-lanes landing shipped), so a spec whose steps declare needs: none puts every step's worktree on disk before a helper is free to take it; ruling DR6d-1 (the product thinker, 2026-10-02) says a step's worktree is made just before an agent takes it, at most the agent ceiling's worth on disk.

The build loop opens a lane for every ready spec step whatever the ceiling, making its worktree and brief at once (schedule.go move, the eager opening the parallel-lanes landing shipped), so a spec whose steps declare needs: none puts every step's worktree on disk before a helper is free to take it; ruling DR6d-1 (the product thinker, 2026-10-02) says a step's worktree is made just before an agent takes it, at most the agent ceiling's worth on disk.

Grounds

• pursued: we expect a run with a ceiling of N and more than N ready steps never to hold more than N step worktrees on disk and to make the next one only when a landing frees one (TestAStepsWorktreeIsMadeOnlyWhenAHelperIsFree); shown wrong if a step's worktree appears while no helper is free to take it