Resolved. A compromised admin token could previously promote accounts or approve/reject moderation flags with no durable record. backend/src/admin-audit now provides an append-only admin_audit_events table (actor, action, target, a SHA-256 payload hash, correlation id, timestamp). A row is written on every role change (UsersController#updateUserRole, admin-only) and every moderation decision (ModerationService#reviewFlag). The log is readable via GET /v1/admin/audit-log (admin-only, 403 otherwise, paginated); there is no update or delete endpoint for audit rows.

Resolved. The canonical runtime stack is backend/src/auth-module with backend/src/users. The deprecated src/auth, src/users-module, and src/refresh-module trees were removed. The global throttler lives under src/common/guards, and historical schema migrations live under src/database/migrations, so deleting deprecated code no longer removes production controls or migration history.

Resolved. GET /v1/health previously reported a static up without probing any subsystem, so an orchestrator (k8s liveness/readiness probe, load balancer health check) could keep routing traffic to an instance whose database connection was completely down. Liveness (GET /v1/health) now stays a cheap process-up check by design — a dependency outage must not restart an otherwise-healthy process — and readiness moved to GET /v1/health/ready, which probes the database (mandatory, 503 on failure) and Redis when configured (mandatory, 503 on failure), while Soroban RPC is probed and reported for visibility only and never fails readiness on its own.