# ADR-0009 Number provenance audit

## Context
Every investment number must be traceable.

## Decision
Require source_ref and formula_id for investment numbers.

## Alternatives
- Allow implicit report numbers

## Consequences
- Ungrounded numbers are detectable

## Rollback
Rebuild the report from a provenance-backed packet.

## Affected files
- tools/validate_number_provenance_v2.py