Yardlet v0.5.1

Changed

• Renamed the project to Yardlet. The crate, binary, and command are now
  yardlet (the yard name was taken on crates.io by an unrelated parser).
  The container-yard metaphor and identity are unchanged. Existing workspaces
  keep working: the config file is now .agents/yardlet.yaml, but a legacy
  .agents/yard.yaml is still read (and written in place) so nothing breaks on
  upgrade. Internal worktree branches stay yard/<task-id>.

Fixed

• Pause/stop now works from the Monitor screen, and the footer stops lying.
  p (graceful pause) and a new x (stop the worker now) work on the Run
  Monitor, not just Home — the monitor was a dead end for both. The Home footer
  no longer advertises p pause during a planning or single-task run (nothing
  to pause between tasks); it shows Esc stop instead, and pressing p there
  now says so explicitly rather than a vague "busy". Esc/x stop the worker
  immediately; p still only pauses an auto-drain (between tasks).