List terminated executors that may still own an on-chain position.

Covers three orphan classes:

• Involuntary holds: close_type POSITION_HOLD with hold_reason set (an LP close that exhausted its retries): the position is live on-chain with no automated owner.
• Legacy FAILED records whose final state still reported a position_address (force-stop stragglers, records persisted by older executors).
• Executors terminated by SYSTEM_CLEANUP after an API restart: their on-chain state was never persisted, so they need external reconciliation.

This is a DB-side listing. Before recovering, cross-check candidates against on-chain reality via the gateway positions-owned endpoints (/trading/clmm/positions-owned, /trading/amm/positions-owned).