Confirm production-only constraints that Hibernate does not declare #96

Production Liquibase declares constraints that the Hibernate reference does not. These are extras to confirm. They are not columns to drop. Hibernate ddl-auto=validate still starts. These rows are INFO, not PROBLEM.

Measured 2026-10-19 with bash tools/scripts/compare-schema-drift.sh both --against jpa --fail-on none. Both dialects:

• STM_SERVICE_USAGE FK SUS_APPID only on production → STM_APP(APP_ID)
• STM_SERVICE_USAGE FK SUS_SERID only on production → STM_SERVICE(SER_ID)
• STM_TASKREL UK TAR_TASKID,TAR_ALIAS only on production
• STM_TOKEN_USER UK USER_ID only on production