Task: Implement and verify counterparty shell and CLI commands

Implement or verify ores.shell and ores.cli commands for counterparty: list, add, remove (and history where applicable), matching the conventions used by other commissioned entities (e.g. party_type).

• Shell list, add, and remove commands work correctly for counterparty.
• CLI equivalents (import/export/list/delete/add per the CLI recipe conventions) work correctly for counterparty.
• Any gaps vs. the party_type baseline are closed or filed as follow-up captures.

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)