#796 Rate limiter function calls missing highway schema prefix

ERROR: function release_rate_token(unknown) does not exist Root cause: Python code in tenant_rate_limiter.py called PostgreSQL functions without 'highway.' schema prefix: - Line 357: consume_rate_token - Line 390: release_rate_token (causing the error) - Line 414: cleanup_expired_rate_leases Functions exist in highway schema only, not in public schema or search_path. Fix: Added 'highway.' prefix to all three function calls. Files modified: engine/policies/tenant_rate_limiter.py Verified: Submitted test workflow, completed successfully with no postgres errors.