0.3.4

• File story:worktree-diff in the planning store this repository already had: one read-only verb
  showing the commits, per-file stat and patch a managed worktree adds over the revision it was
  created from, with a path filter and a JSON form. Filed, not implemented.
• Remove the nested duplicate store .engineering/.engineering/ that 0.3.3 added by mistake;
  0.3.3's changelog line claiming to adopt the store was wrong — the store predates it.