Design decisions

• Numbers in code: models read and choose; maths is deterministic
• Gateway re-checks: never trust agent-supplied prices or policy
• Diet loaded in full: no similarity miss on allergens (vectors later assist match only)
• Same policy library: engine pre-check + gateway authority
• MCP = REST: one handler, two transports
• Telegram as channel: thin client, same signatures
• Observe ≠ authorize: OTel / Langfuse tune agents; they never sign offers
• Next data plane: PostgreSQL + vector DB for multi-tenant scale