# ADR-0005 Formula domain split

## Context
The monolithic formula registry needs domain separation.

## Decision
Split formulas by domain and build a normalized registry.

## Alternatives
- Keep a single registry file

## Consequences
- Review scope is reduced
- Formula ownership is easier to track

## Rollback
Rebuild normalized registry from the monolith.

## Affected files
- spec/formulas/*
- spec/03_formulas/formula_registry.normalized.yaml