ADR 0001: Record architecture decisions with ADRs

Status

Accepted

Context

The project spec (section 8) requires that major structural choices be documented with why, not just what, from the first commit — so future contributors can extend the system without reading the whole codebase or re-litigating settled decisions.

Decision

We record architecturally significant decisions as Architecture Decision Records under docs/adr/, numbered sequentially, using the template in docs/adr/template.md. A decision is ADR-worthy if reversing it later would require touching multiple modules or would be expensive/risky — not every implementation detail needs one.

Consequences

Decision history is greppable and versioned alongside the code it affects. Superseding a decision means adding a new ADR that references the old one, not editing history.