Dead field — was enforced by compact ctor as required for PER_EXCHANGE, but never read anywhere in the codebase. Removal tightens the API surface and is precondition for the Task 3.3 cross-field validator. Pre-prod; no shim / migration.
Dead field — was enforced by compact ctor as required for PER_EXCHANGE, but never read anywhere in the codebase. Removal tightens the API surface and is precondition for the Task 3.3 cross-field validator. Pre-prod; no shim / migration.