Task: Add missing EXPORT macros to service classes

Every *_service class meant to be called across .so boundaries (party_service, portfolio_service, and 17 other refdata services, plus scheduler's job_definition_service) is missing its ORES_<COMPONENT>_CORE_EXPORT annotation. With the project's -fvisibility=hidden default, this makes their methods unresolvable from any other shared library or executable, surfacing as undefined-reference linker errors (discovered via ores.iam.core.tests failing to link against party_service::get_party_at_version and counterparty_service::get_counterparty_at_version, and counterparty_repository::read_at_version needing a stale .o recompile). Add the export.hpp include and EXPORT macro to every affected class; leave *_mapper classes alone since those are internal-only, never called cross-.so.

• All 19 ores.refdata.core service classes and ores.scheduler.core's job_definition_service carry their EXPORT macro.
• ores.iam.core.tests and a full project build link cleanly with no undefined-reference errors.

(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.)

Manual QA scenarios (scaffolded via compass add test_scenario, run through the QA Validation Runner panel) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

Added the export.hpp include and ORES_REFDATA_CORE_EXPORT=/=ORES_SCHEDULER_CORE_EXPORT macro to all 19 affected ores.refdata.core service classes plus ores.scheduler.core's job_definition_service; *_mapper classes were deliberately left alone as internal-only. Also touched counterparty_repository.cpp to force a recompile of a stale .o missing read_at_version. Verified with a full clean build and a full local rat run (54 suites, all green) — no undefined-reference errors remain.