feat: Enhance audit capabilities with database trigger and correlation ID propagation - Added documentation for the new Database Trigger Audit Process, detailing the trigger flow, transaction behavior, and test coverage. - Introduced the Audit Tables component, outlining the PostgreSQL audit_event and audit_change schema. - Created a reference for the CorrelationIdConnectionProvider, a Hibernate decorator for injecting Micrometer B3 trace IDs into PostgreSQL. - Documented architectural decision ADR 001 regarding the deferred-bind ConnectionProvider for transaction-local GUC. - Updated existing documentation to reflect changes in migration safeguards, integration scenarios, and actor fallback behavior.