Retire the unproduced rpa_instruments table

Retire ores_trading_rpa_instruments_tbl and the ores.trading.rpa_instrument model behind it, once the credit family has decided where the risk participation agreement's own facts live.

RiskParticipationAgreement routes to credit_instrument, so nothing writes the rpa_instruments table and nothing reads it. Before the routing repair the generated route pointed at rpa_instruments while the ORE importer wrote credit_instruments, whose check refused the code: the import was refused and the export found no row to rebuild from.

The table's own columns — reference_counterparty, participation_rate and protection_fee — were never written by any mapper, and the credit mapper does not fill them either. They are the credit family's RPA facts, so the credit family decides whether they get a home or are not persisted.

Retiring a generated entity is its own unit: it touches the model, the generated C++ and SQL, the shell command unit and its recipe, and the rpa_instrument leaf of the rates wire variant, and no tool prunes the files it leaves behind.

Done, not discarded for lack of merit. The credit story's task retire-the-unproduced-rpa-instruments-table retires the table, so this capture has no work left. It is filed here to leave the inbox.

• The routing repair that made the table unreachable: Rework the rates instruments to the instrument table rule, task repair-the-rates-routing.
• The family analysis that recorded the contradiction: findings R1, R2, R8 and R19 of the rates story's design.org.

• ores.refdata.asset_class_catalogue — the taxonomy that classes RiskParticipationAgreement credit.