# spec.md — <change-id>

## Title
<change title>

## Legacy context
This change touches the following legacy surfaces:
- <surface>
- <surface>

## Why now
<why this change matters now>

## In scope
- <item>
- <item>

## Out of scope
- full rewrite of <module>
- cleanup unrelated to affected paths

## Acceptance criteria
- [ ] existing characterization tests still pass
- [ ] no contract regressions on <boundary>
- [ ] new behavior meets <criterion>
- [ ] migration notes documented if applicable

## Blast radius
- files/modules likely affected:
  - <path>
  - <path>

## Rollback trigger
Rollback if:
- <condition>
- <condition>
