chore(release): prepare 0.8.28-alpha.1

[lavaman131]

Summary

Finalizes changelog entries for the 0.8.28-alpha.1 prerelease across coding-agent and workflows packages.

Key Changes

• packages/coding-agent/CHANGELOG.md: Moves the verbatim-compaction critical-overflow reasoning-trace eviction change (Enhance verbatim compaction overflow eviction for reasoning traces #1308) from [Unreleased] into the [0.8.28-alpha.1] section, since that code ships in this prerelease. Corrects the release date to 2026-06-09.
• packages/workflows/CHANGELOG.md: Corrects the [0.8.28-alpha.1] release date to 2026-06-09.

Notes

• Changelog-only changes; no source, config, or lockfile modifications.
• Package versions were already bumped to 0.8.28-alpha.1 in feat(compaction)!: remove summary compaction in favor of verbatim #1313 but no tag was cut; this PR completes the release notes so the published prerelease is accurate.
• The bundled intercom, mcp, subagents, and web-access extensions carry no functional changes since 0.8.27 (version-bump only) and receive no new changelog sections.
• After merge, the 0.8.28-alpha.1 tag will be pushed to trigger the Publish workflow (@bastani/atomic).

[claude]

PR Review — chore(release): prepare 0.8.28-alpha.1

Reviewed against CLAUDE.md (Changelog + Releasing conventions). This is a tidy, low-risk changelog-only PR. I verified the claims against the repo state and they hold up.

✅ Verified

• All six workspace packages are already at 0.8.28-alpha.1 in package.json — confirmed; no version/lockfile churn in this PR, matching the description.
• No 0.8.28* git tag exists yet, consistent with the "tag never cut" rationale.
• Folding the #1308 critical-overflow eviction entry out of [Unreleased] into [0.8.28-alpha.1] is correct: since the versions were bumped in feat(compaction)!: remove summary compaction in favor of verbatim #1313 but no tag was cut, anything on main ships under this tag. The entry is preserved verbatim and lands under the existing ### Changed subsection (no duplicate subsection created — good, per the changelog rules).
• Re-dating the coding-agent and workflows sections to 2026-06-09 matches today's date and stays after the 0.8.27* entries (2026-06-08). Ordering is monotonic.
• Both [Unreleased] sections are now empty rather than left with a dangling empty ### Changed header — clean.
• No already-released section was modified (only the not-yet-tagged 0.8.28-alpha.1 and [Unreleased]), respecting the immutability rule.

🟡 Worth a look (non-blocking)

1. Bundled extensions have a version with no changelog section. intercom, mcp, subagents, and web-access are all at 0.8.28-alpha.1 in package.json, but their latest changelog section is still [0.8.27]. The PR justifies this as version-bump-only, which is a reasonable call — but it does mean a published version number with no corresponding ## [0.8.28-alpha.1] entry. If the release flow or any tooling expects every published version to have a section, consider adding a minimal stub (e.g. a one-line _No functional changes; version aligned with the workspace release._) for traceability. Otherwise this is fine to leave as-is.

2. Date vs. actual tag date. The section is dated 2026-06-09, but the tag is to be cut after merge. If the merge/tag slips to a later day, the changelog date will be slightly ahead of the actual release. Minor — just cut the tag same-day, or re-date if it slips.

Code quality / bugs / perf / security

N/A — documentation-only diff (Markdown changelogs). No source, schema, lockfile, or test changes, so nothing for test coverage either.

Nice, careful release hygiene. ✅ LGTM pending the optional extension-changelog consideration above.

Reviewed by Claude (Opus 4.8).