“Show me that your AI cannot write to the schedule.”

• Every question routes to a closed, fixed catalogue of engine-backed answers.
• Every number is computed by a deterministic tool — the model never does arithmetic.
• Anything outside the catalogue is refused with fixed text, not model narration.
• The AI runs on its own database role, with INSERT revoked on every authoritative table.
• A post-answer check re-verifies every figure against the source; a mismatch fails the response.

vantomic_agent=> INSERT INTO fact
                 (activity_id, fact_type_code)
                 VALUES (…);

ERROR:  permission denied for table fact
SQLSTATE: 42501 (insufficient_privilege)

The agents run in a separate process that holds no privileged database credential at all — so there is nothing to misuse.