ADR 001: why refund eligibility is deterministic Java, not a model judgment

Part 3 of an ongoing experiment: building an LLM-powered support agent with deterministic boundaries. The companion repo grows with the series.

Post 2 gave us the ruler: facts with high cost and assertable answers belong to software. This post applies it to the most consequential component in the system — refund eligibility — and documents the decision as we've actually recorded it, in ADR form.

The option that almost won

The LLM-decided version writes itself: