API surface changes documented

Published libraries without a changelog force consumers to diff two arbitrary git SHAs to understand what changed between versions — or to discover breaking changes at runtime after an upgrade. ISO 25010:2011 §6.5.2 classifies undocumented API surface changes as a maintainability defect. For internal applications this is low priority, but any package with "private": false or published "exports" fields is making an implicit promise to consumers that it does not keep when it ships breaking changes silently.

Add a CHANGELOG.md at the repo root following the Keep a Changelog format. Include a "Breaking Changes" section for any major or minor releases that remove or modify public API behavior.

# Changelog

## [Unreleased]

## [1.2.0] - 2024-03-15
### Added
- New `formatCurrency` utility function

### Changed
- `parseDate` now returns `null` instead of throwing on invalid input

### Breaking Changes
- Removed deprecated `formatMoney` function; use `formatCurrency` instead

Consider release-please or standard-version to generate changelog entries automatically from conventional commits.

• ID: breaking-changes-doc

• Severity: info

• What to look for: Check for a CHANGELOG.md file in the project root. For projects that are published as libraries or packages (check package.json for "private": false or presence of "main", "exports", "files" fields), a changelog is important for consumers to understand breaking changes. For internal applications, this is informational — nice to have but not critical. Look for semantic versioning in use (version field in package.json follows semver). Check whether git tags are used for releases.

• Pass criteria: Enumerate all relevant code locations. CHANGELOG.md exists and documents version history, OR project is an internal application (not a published library) with at least 1 verified location.

• Fail criteria: Project is a published library without a changelog.

• Skip (N/A) when: Internal application, not a library or public API.

• Detail on fail: "No CHANGELOG.md found; consumers of this library cannot track breaking changes between versions"

• Remediation: Add a CHANGELOG.md following the Keep a Changelog format:

  # Changelog
  
  ## [Unreleased]
  
  ## [1.2.0] - 2024-03-15
  ### Added
  - New `formatCurrency` utility function
  
  ### Changed
  - `parseDate` now returns `null` instead of throwing on invalid input
  
  ### Breaking Changes
  - Removed deprecated `formatMoney` function; use `formatCurrency` instead
  

  Consider using standard-version or release-please to automate changelog generation from conventional commits.