# ConfigKit v0.4.0

This release renames selected configuration profiles to overlays, intentionally
breaking the previous naming contract without compatibility aliases or fallback.

## Summary

Selected configuration now uses `Options.Overlay` and `overlays/<name>.yml`.
Selection, merge rules, input precedence, and lifecycle behavior are unchanged.
See the [selected-overlay contract](../config.md#selected-overlays).

## Compatibility

This is a breaking minor release before v1.0.0. Four surfaces change:

- Go API: `Options.Profile` becomes `Options.Overlay`, `LayerProfile` becomes
  `LayerOverlay`, and all seven `CodeProfile*` constants become `CodeOverlay*`.
- Selected files: `profiles/<name>.yml` becomes `overlays/<name>.yml`; there is
  no legacy-directory fallback.
- Provenance: the layer string changes from `profile` to `overlay`.
- Structured diagnostics: the `profile.*` code prefix becomes `overlay.*`.

The old Go identifiers are removed. Application-owned concepts such as
`ModelProfile` and `model_profile` are unchanged. Ordinary explicit imports from
a directory named `profiles` remain valid base inputs.

The minimum Go version remains 1.25. Linux remains release-validated and macOS
remains best-effort. The YAML dependency remains pinned to
`go.yaml.in/yaml/v4 v4.0.0-rc.6`; this release does not change parser dependencies.

## Upgrade

Update the dependency:

```sh
go get gitea.maximumdirect.net/eric/ConfigKit@v0.4.0
```

Rename the affected Go identifiers, move selected files into `overlays/`, update
any handling of provenance-layer and diagnostic-code strings, and rebuild.
The maintained example helper is now `LoadNarratioOverlay` rather than
`LoadNarratioProfile`. Application CLI flag names remain application-owned;
ConfigKit does not require renaming domain-specific profile concepts.
See the [migration guide](../consumers/README.md#selected-overlay-migration).

## Changes

- Rename the selected feature consistently across the public facade, internal
  engine, diagnostics, source labels, examples, and current documentation.
- Add regression coverage for the new directory, absence of legacy fallback,
  public values, explanations, and preservation of application profile fields.
- Align contributor policies with the current shared standard.
- Simplify release validation to one local minimum-toolchain check. CI is not a
  release gate; successful publication of the intended tag completes the
  source-only release. See the [release procedure](../release.md).
- Retire completed overlay and release-workflow planning documents to Git history.