[codex] Drive changelog releases from towncrier

[adamtheturtle]

Summary

This switches release changelog handling to the same towncrier-based flow used by literalizer:

• replace the manual Next changelog section update with towncrier build
• generate GitHub release notes from the same news fragments
• add the towncrier config, template, and newsfragments/ directory
• render unreleased fragments in docs where the project has Sphinx docs
• migrate any existing Next entries into initial news fragments

Validation

• uv run --extra=release towncrier build --draft --version 2099.01.01
• uvx --from actionlint-py actionlint .github/workflows/release.yml
• uv run --extra=dev pyproject-fmt --check --no-print-diff pyproject.toml where the repo has a dev extra
• repo pre-commit / pre-push hooks run by git commit and git push

---

Note

Medium Risk
Updates the release pipeline to build both CHANGELOG.rst and GitHub release bodies from towncrier fragments, which could affect tagging/release automation if the workflow or towncrier config is mis-specified. Also changes doc builds to render unreleased notes, adding new dependencies and potential CI/doc gate failures.

Overview
Switches release automation from a manually-edited Next section to towncrier-driven release notes. The GitHub Actions release workflow now runs towncrier build to (1) emit curated GitHub release notes (release-notes.md) and (2) update CHANGELOG.rst, committing both the changelog update and consumed newsfragments/.

Adds towncrier support across the repo: a newsfragments/ directory, a custom docs/towncrier_template.rst.jinja, and [tool.towncrier] config in pyproject.toml (plus new towncrier/sphinxcontrib-towncrier dev deps). Docs now include an Unreleased changes page (docs/source/unreleased.rst) rendered from draft fragments during Sphinx builds, and CHANGELOG.rst is anchored with .. towncrier release notes start for insertion.

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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Towncrier missing from release extra

High Severity

The release workflow runs towncrier via uv run --extra=release, but towncrier is only declared under optional-dependencies.dev, not optional-dependencies.release. The release job environment therefore will not install towncrier, so changelog and release-notes steps should fail before tagging or publishing.

Additional Locations (1)

• pyproject.toml#L88-L98

 

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