pm: bump to ghostel fresh-buffer dispatch + hidden stderr buffer

- pm-agent ghostel dispatcher now passes a non-numeric prefix so
every launch lands in a freshly named buffer (no more pasting
argv into a live agent's REPL on the second launch).
- pm-process renames the per-verb stderr buffer to a leading-space
name so the "Process … stderr finished" trailer no longer shows
up in the buffer list after `pm-refresh` on init.